Duro Alloy-Steel Tools
Duro's first alloy steel tools were probably the chrome-nickel socket sets introduced in 1931.
However, it's possible that forged alloy steel wrenches could have been in production before the
socket sets —
Duro is believed to have had in-house drop forging capabilities by the early 1930s,
and thus might have started producing open-end wrenches,
as competitors such as Hinsdale Manufacturing had done.
The Chrome-Vanadium Era
Duro's early wrenches were made using chrome-vanadium steel and socket production soon followed.
Chrome-vanadium steel remained the company's preferred alloy through the 1930s and into the 1940s.
Although Duro didn't mark its socket tools for alloy content,
wrenches in both the Handy-Hex and the Duro-Chrome brand were marked with "Chrome-Vanadium".
These specific alloy content markings continued up until the mid wartime years,
but then were discontinued.
(Other companies also discontinued specific alloy markings midway through the war,
leading us to wonder if there had been a directive from the War Production Board.)
Post-War Alloy Usage
In the post-war era alloy content was no longer marked on tools,
as by then tool buyers expected appropriate alloy content anyway.
The Duro catalogs of this era consistently listed "Chrome Alloy Steel" for the higher-grade tools,
but without any further detail on actual alloy usage.
With no further information we might have thought that Duro continued to use chrome-vanadium steel,
but the chance discovery of a newpaper ad provides a different view.
The scan in Fig. 272 shows
an advertisement placed by Duro Metal Products to sell surplus steel stock,
found on page 78 of the December 4, 1949 edition of the Chicago Tribune.
The ad lists one lot of C1045 steel, a medium carbon tool steel,
and numerous lots of 8642 steel, a nickel-chrome-molybdenum alloy widely used for top-grade tools.
AISI 8642 steel (and the similar 8742 alloy) are known to have been used extensively by Herbrand
via forged-in markings on tools,
and some Williams tools tested for alloy content showed a composition similar to these alloys.
(See for example the Herbrand 6923 Wrench
or the Williams 1027 Wrench.)
Although one ad to sell excess steel doesn't prove that Duro used 8642 steel on a continuing basis,
it strongly suggests that Duro was a major buyer and user of this alloy.
Sockets and Drive Tools
By 1931 Duro was offering socket sets with chrome-nickel alloy sockets.
The confirmation comes from the 1931 Sears catalog,
which lists several socket sets under Duro's "DuroBilt" brand,
including a "Super DuroBilt" 40-piece set featuring chrome-nickel sockets.
At this time 6-point sockets were still standard,
but 12-point sockets were available at a slightly higher price.
Fig. 273 shows
a catalog listing for another early Duro chrome-nickel socket set,
found on page 73 of the 1932 J&R Motor Supply catalog.
The illustration shows a forged-body ratchet with the Duro name visible,
which one of our readers reports is a Duro 675 ratchet.
This female-drive model was constructed with a forged handle and two cover plates
securing the mechanism.
Shortly after this time Duro developed their well-known
Pressed-Flange Ratchet,
the patent for which was filed in mid 1932.
Duro's earliest alloy-steel socket sets were all in 1/2-drive,
but tools in 1/4, 3/8, and 3/4-drive soon followed.
The examples here for other drive sizes have been ordered by
3/8-Drive, 1/4-Drive,
and 3/4-Drive.
Duro-Chrome 678D 1/2-Drive Reversible Ratchet
One of the more notable Duro inventions described a novel way for constructing ratchets.
Instead of a conventional ratchet assembly held together with screws or rivets,
the Duro design secured the parts with a pressed flange integral to the forging.
This allowed Duro to produce a high-quality forged ratchet at a reasonably low cost,
and the resulting products were sold widely into high-volume markets.
Duro applied for a patent on the design in 1932 and was issued patent
#1,902,878 in 1933.
Fig. 274 shows
an example of the pressed-flange design,
a 1/2-drive Duro-Chrome model 678D reversible ratchet,
marked with a bold "Duro-Chrome" on a raised panel in the center of the forged handle.
The back side shows a similar panel with "Made in U.S.A." and "Pat. No. 1902878".
The overall length is 10.4 inches,
and the finish is plain steel with a dark oxide coating.
This ratchet has a fairly coarse 18-tooth gear,
but later versions of this model had a 36-tooth mechanism for a much finer action.
The combination of the coarse action and plain finish suggests that this may be a very early model,
possibly dating to the early 1930s.
One interesting feature is the provision of both male and female drive,
as can be seen in the photograph.
Male drive ratchets were becoming more popular in the 1930s and were gradually replacing the older female models.
By providing both drive genders,
Duro allowed the ratchet to work with older sets having double-male extensions and drive plugs.
The 1935 Duro catalog also offered a similar model 677D non-reversible ratchet,
fitted with a female-only drive gear.
The pressed-flange ratchet design remained in production at least until the early 1960s,
with catalog 37-M offering a model 676 female drive ratchet with a 36-tooth action.
Probably the first market for these ratchets,
and perhaps the impetus for their development,
was as part of the "Chrome-Vanadium Socket Wrench Set" offered in the
1933 Western Auto Catalog.
This set sold for a mere $5.68 and included the ratchet,
a speeder, a sliding Tee handle, two extensions, a universal, and ten 12-point sockets,
truly a stunning value for a set of alloy steel tools.
(This set was very similar to the
Indestro Chromium Vanadium 17-Piece Socket Set mentioned earlier,
with the ratchet adapter replaced by the pressed-flange ratchet.)
Duro-Chrome 4487 1/4-Drive Ratchet
Fig. 275 shows
a Duro-Chrome model 4487 1/4-drive reversible ratchet,
marked with "Duro-Chrome" forged into a raised panel on the handle,
with "Made in U.S.A." and "Pat. No. 1902878" forged into the back side.
The overall length is 6.0 inches,
and the finish is cadmium plating.
The ratchet mechanism has a 20-tooth gear and is fitted with a reversing lever,
as with the previous example.
This ratchet also offers both male and female drive.
The Development of Hot-Broached Sockets
In May of 1935 Duro filed for an important patent on their new hot-broaching method for
making sockets,
and the patent was issued as #2,027,922 in January, 1936.
The patent document has an excellent discussion of the prior art (cold-broaching) and
the advantages of hot-broaching,
and is highly recommended for anyone interested in the how and why of such things.
The scan in Fig. 276 provides a description and illustration of the hot-broaching process,
as found on page 3 of the 1946 Duro catalog.
Among the advantages cited are the increased strength of the sockets,
the smooth broach free of chatter marks,
and the relieved lip at the drive end that allows for easier connection to a drive tool.
(The patent even mentions the attractive "scalloped" appearance of the metal pushed ahead
of the broach.)
Duro-Chrome 699 1/2-Drive Dual-Pawl Ratchet
During the 1930s and 40s much effort was devoted to improving ratchet mechanisms,
especially for the "round-head" designs with fine-tooth actions.
While others looked for ways to make finer teeth,
the engineers at Duro Metal Products came up with a novel idea.
Instead of adding more teeth to the gear,
they added a second pawl to the mechanism,
with the teeth of one pawl offset from the other by half a pitch.
Then as the ratchet turned to get a new "bite",
the pawls would alternately drop into position,
thereby effectively doubling the number of teeth.
The inventor W.H. Odlum and collaborators were awarded
patent #2,395,681 in 1946.
Fig. 277 shows
an early example of the Duro-Chrome 699 1/2-drive dual-pawl ratchet,
marked with "U.S.A." and "Pat. Pend." on the cover plate.
The overall length is 10.5 inches,
and the finish is chrome plating.
The "Pat. Pend." notation indicates that this is an early production model;
based on the patent filing and issue dates,
the likely manufacturing date is in the range 1944-1946.
The dual-pawl action can be heard clearly when the ratchet is turned slowly,
with the two pawls making slightly different clicking sounds as they fall into place.
The Duro catalogs advertised this as having "80 tooth action" without describing
its 40-tooth gear and dual pawls.
One interesting aspect of the construction is that the ratchet has been permanently assembled
by compressing flanges in the head.
This technique was invented by Duro in the early 1930s
(as patent #1,902,878)
and used for a series of ratchet models.
(The patent also appears to have been used by Hinsdale;
see for example the H-12-R Ratchet.)
Although the dual-pawl mechanism was a great idea,
this ratchet model was apparently not very successful as a product.
Two factors probably contributed to its limited success:
first, the patent design required two different pawls,
one with the teeth offset,
and having to make two precision parts would have increased the manufacturing cost.
Secondly,
the permanent assembly negated one of the potential advantages of the round-head ratchet design,
the simple replacement of the ratchet mechanism as a unit.
This could have been significant when the manufacturer offered a lifetime warranty for its tools,
as it would mean replacing the entire unit instead of offering (selling!) an inexpensive renewal kit.
As a result of these issues (or others),
by 1955 Duro-Chrome had already discontinued this model.
(The 1955 catalog still illustrates this ratchet model,
but the price list substitutes a more conventional
Duro-Chrome 675 Ratchet with a 52-tooth design.)
Although not a big success for Duro-Chrome,
the dual-pawl patent did pave the way for great products from other companies.
In the early 1950s,
W.J. Johnson at J.H. Williams & Company made a brilliantly simple (or simply brilliant) improvement
to the design.
Johnson's ratchet is described by patent
#2,772,763 and uses symmetrical dual pawls,
but with an odd number of teeth in the drive gear,
thereby gaining the same benefit with a simpler mechanism.
This resulted in the Williams S-52 (and related) ratchets,
arguably one of the best ratchet designs of all time.
Some years later,
H.J. Haznar at Moore Drop Forging updated the dual-pawl design with an improved shift mechanism
and a quick-release button,
for which he received patent
#3,467,231.
These features were used for the excellent
Craftsman "V" Dual-Pawl Ratchets,
a very popular and highly successful series introduced in the late 1960s.
Duro-Chrome 675 1/2-Drive Ratchet
Fig. 278 shows
a 1/2-drive Duro-Chrome 675 ratchet,
marked "Duro-Chrome U.S.A." at the end of the handle.
The overall length is 10.2 inches,
and the finish is chrome plating with a polished head and shank.
The ratchet mechanism is a variant of the classic S-K design and uses a 52-tooth
gear in the drive handle.
The shift mechanism incorporates a detent ball to guard against accidental shifting,
and is described by Duro patent
#2,686,582,
issued in 1954.
This ratchet model was first listed in a supplement (35S) to the 1955 Duro catalog No. 35,
and was intended as a replacement for the discontinued
Duro-Chrome 699 Dual-Pawl Ratchet.
The 1961 Duro catalog listed both the model 675 and a similar model 689 with a longer handle.
The equivalent tool in the Indestro Super line is the
Indestro 3275 Ratchet.
Other examples of similar models include the
Wizard H2833 Ratchet.
Duro-Chrome 666D 1/2-Drive 11 Inch Flex-Head Handle
Fig. 279 shows
a Duro-Chrome 666D flex-head handle,
marked "U.S.A." with the Duro-Chrome trademark.
The overall length is 11.4 inches,
and the finish is chrome plating.
The knurled handle is equipped with a cross-bar hole and has a 1/2-drive stud on the end.
The latter feature was popular on earlier breaker bars,
when female-drive ratchets were the norm,
as it allowed the breaker bar to operate as an extension.
The knurled handle is equipped with a cross-bar hole and a 1/2-drive stud,
allowing additional functionality as a Tee-handle and extension.
Duro-Chrome 657DK 1/2-Drive 15 Inch Flex-Head Handle
Fig. 280 shows
a Duro-Chrome 657DK flex-head handle,
marked "U.S.A." with the Duro-Chrome trademark.
The overall length is 15.5 inches,
and the finish is chrome plating.
The knurled handle is equipped with a cross-bar hole and a 1/2-drive stud,
allowing additional functionality as a Tee-handle and extension.
Duro-Chrome 669D 1/2-Drive 18 Inch Flex-Head Handle
Fig. 281 shows
a 1/2-drive Duro-Chrome 669D 18 inch flex-head handle,
marked "U.S.A." with the Duro-Chrome trademark.
The overall length is 17.6 inches,
and the finish is chrome plating.
The knurled handle is equipped with a cross-bar hole for use as a Tee-handle,
but the end is not broached for square drive.
Earlier versions of this model did include a 1/2-drive broached end,
allowing use as an extension.
Duro-Chrome 663D 1/2-Drive Sliding Tee Handle
Fig. 282 shows
a 1/2-drive Duro-Chrome 663D sliding Tee handle,
stamped "Duro-Chrome" on the shank.
The overall length is 11.6 inches,
and the finish is plain steel.
Duro-Chrome 582 1/2-Drive 3 Inch Extension
Fig. 283 shows
an early 1/2-drive Duro-Chrome 582 3 inch extension,
stamped "Duro Chrome" on the shank.
The overall length is 3.1 inches,
and the finish is nickel plating.
The extension is equipped with a 3/8 inch diameter cross-bar hole for use as a Tee-handle.
Duro-Chrome 662D 1/2-Drive 3 Inch Extension
Fig. 284 shows
a later 1/2-drive Duro-Chrome 662D 3 inch extension,
stamped "Duro-Chrome" and "U.S.A." on the drive head.
The overall length is 3.1 inches,
and the finish is polished chrome.
The extension is equipped with a 3/8 inch diameter cross-bar hole for use as a Tee-handle.
Modern Sockets
Duro and Indestro must have been very busy during the late 1930s,
as their socket lineup developed very rapidly in these years.
By the time of the 1938 Duro-Chrome catalog (38M),
almost all of the modern series of sockets had been developed,
and the sockets had been assigned part numbers.
These included the 1/2-drive 11xx, 16xxx, 12xx, and 14xx (deep) series sockets,
the 3/8-drive 44xx series, and the 1/4-drive 45xx series.
Duro-Chrome 1/2-Drive 11xx and 16xx Sockets
Fig. 285 shows
the top-of-the-line for Duro-Chrome's 1/2-drive sockets,
the 11xx series with thin straight walls and 16xx series for thin tapered walls.
These included selected 8-point sizes (marked by appending an "S" to the model number)
and the specialty 1618V8XY socket,
the latter made with ultra-thin walls for certain connecting-rod bolts.
The models and sizes are, from the left, 1118 (9/16), 1618V8XY (9/16), 1625 (25/32),
and 1622S (11/16, 8-Point).
Duro-Chrome 1618V8X 1/2-Drive 9/16 Connecting Rod Socket
Duro-chrome's 16xx series of 1/2-drive sockets included a special 9/16 socket,
made with extra-thin walls for Ford connecting-rod applications.
Although the 16xx sockets were otherwise all double-hex,
this special socket was available in both hex and double-hex broachings,
with model numbers 1618V8X and 1618V8XX respectively.
Fig. 286 shows
a 1/2-drive Duro-Chrome 1618V8X 9/16 hex socket,
stamped "U.S.A." on the base.
The lower-right inset shows the hot-broached construction of the socket.
This socket was intended for Ford connecting-rod applications,
which required very thin walls for clearance.
Impact Sockets
Duro didn't offer impact sockets until sometime in the 1950s.
Duro-Chrome 1174 1/2-Drive 3/4 Impact Socket
Fig. 287 shows
a 1/2-drive Duro-Chrome 1174 3/4 impact socket,
stamped "U.S.A." on the base.
The finish is chrome plating.
This early impact socket shows the surprising use of a chrome plated finish
with a cross-hatched band,
similar to the Duro-Chrome standard sockets.
3/8-Drive Tools
Socket tools in 3/8-drive were listed in the 1935 Duro catalog,
currently our earliest Duro resource.
Duro-Chrome 4479 3/8-Drive Flex Handle
Fig. 288 shows
a 3/8-drive Duro-Chrome 4479 flex handle,
stamped "Duro-Chrome" on the shank.
The overall length is 8.7 inches,
and the finish is plain steel.
The plain finish suggests a 1942-1945 manufacturing date.
The knurled handle is broached for a 3/8-drive connection,
as shown in the right inset.
This feature allows the breaker bar to be used as an extension as well.
Duro-Chrome 4481 3/8-Drive Flex Handle
Fig. 289 shows
a 3/8-drive Duro-Chrome 4481 flex-head handle,
marked "U.S.A." near the end of the knurled handle.
The overall length is 9.3 inches,
and the finish is chrome plating with a polished head and shank.
44xx 3/8-Drive Sockets
The 1938 Duro catalog lists the 44xx series of Duro-Chrome 3/8-drive sockets,
but for some reason this drive size was not yet available in the tapered thin-wall
format offered in 1/2- and 1/4-drive.
Instead, the catalog illustration shows these sockets as having narrowed bases and straight walls.
An example of this can be seen in the leftmost socket of Fig. 290,
marked as Duro-Chrome 4420 with size 5/8.
The tapered-wall format was made available later,
as the middle and righthand sockets in Fig. 290 illustrate.
These sockets, marked 4414 7/16 and 4422 11/16 respectively,
both show the same fine cross-hatching that was used for the 1/2-drive 11xx and 16xx series
(see the Duro 1/2-Drive Sockets above.)
The middle socket shows two other interesting details:
the socket is in unfinished steel rather than polished chrome,
and it has a small "G" next to the model number.
We have a number of other Duro tools that also show a "G" marking paired with unfinished steel,
and the "G" marking is believed to indicate a 1945 production date,
when government wartime rationing was in effect.
(The "G" marking was also used as a date code for 1945 on Snap-On tools.)
Duro-Chrome 4535 1/4-Drive Sliding Tee Handle
Fig. 291 shows
a 1/4-drive Duro-Chrome 4535 sliding Tee Handle,
stamped "Duro-Chrome" and "U.S.A." on the top of the sliding head.
The overall length is 4.5 inches,
and the finish is chrome plating.
Duro-Chrome 4575A 1/4-Drive Ratchet
Fig. 292 shows
a 1/4-drive Duro-Chrome 4575A ratchet,
marked "U.S.A." on the shift knob.
The overall length is 4.9 inches,
and the finish is chrome plating with a polished head and shank.
Duro-Chrome 4571 1/4-Drive Flexible-Shaft Drive Handle
Fig. 293 shows
a Duro-Chrome 4571 1/4-drive flexible-shaft drive handle,
marked "Duro-Chrome" and "U.S.A." on the plastic handle.
The overall length is 7.1 inches,
and the finish is plain steel.
In the mid 1930s Duro registered the "Spin-Flex" tradmark for a line of handles and nut drivers
with flexible shafts made with a stiff spring.
Although not marked with the trademark,
this tool is an example of the "Spin-Flex" line.
3/4-Drive Tools
Duro was offering heavy-duty 3/4-drive socket tools by 1935 or earlier.
We have a substantial selection of these tools (including socket sets) and will expand
this section as time permits.
Duro-Chrome 41xx 3/4-Drive 12-Point Sockets
Fig. 294 shows
a group of three Duro-Chrome 41xx 3/4-drive 12-point sockets,
stamped "Duro-Chrome" with the model number and fractional size.
The socket models and sizes are, from the left,
4128 (7/8), 4131 (31/32), and 4132 (1 Inch).
The finish is chrome plating,
with a matte finish on the base and polished upper walls.
The top inset shows the drive end of the sockets,
illustrating the relieved edges of the drive openings.
This was a convenience feature easily added when hot-broaching the opening.
Duro-Chrome 4152 3/4-Drive 1-5/8 12-Point Socket
Fig. 295 shows
a Duro-Chrome 4152 3/4-drive 1-5/8 12-point socket,
stamped "Duro-Chrome" with the model number and fractional size.
The socket has a stepped base and a decorative groove at the transition
to the tapered upper walls.
The finish is chrome plating,
with a matte finish on the base and polished upper walls.
The right inset shows the broached interior of the socket,
with an annular shelf of displaced metal characteristic of Duro's
Hot-Broaching Process.
The left inset shows the drive end of the socket.
Note the relieved edges of the drive opening,
a feature designed to help depress the friction ball when inserting a drive tool.
These relieved edges could be added easily by a suitable mandrel during the hot-broaching process.
A close look at the center of the right inset shows a circular indentation on the drive wall,
a feature to help the drive tool grip the socket.
All four walls have an indentation,
and the indentations appear to have been drilled at an angle after the drive end was broached.
This is a different approach from that taken on other early 3/4-drive sockets such as the
Super-Quality [2248] 3/4-Drive Socket,
where a groove was cut in the drive end prior to broaching,
but which required cold-broaching the drive end to avoid filling in the groove.
Open-End Wrenches
Duro probably started offering open-end wrenches in the early 1930s.
By the time of the 1935 Duro catalog,
Duro-Chrome open-end wrenches were available in industry-standard sizes ranging from No. 1721 (5/16x3/8)
up to No. 1737 (1-1/8x1-1/4).
The wrench markings at this time already included the familiar "Forged in U.S.A." along a curved arc,
as can be seen in the
Duro-Chrome Wrench Markings
in our section on tool identification.
Duro-Chrome 1723 3/8x7/16 Open-End Wrench
Fig. 296 shows
a Duro-Chrome 1723 3/8x7/16 open-end wrench,
stamped "Forged in U.S.A." in a curved arc on the back side face.
The overall length is 5.0 inches,
and the finish is chrome plating with polished faces.
Duro-Chrome "G" 1025 1/2x19/32 Open-End Wrench
Fig. 297 shows
a Duro-Chrome 1025 1/2x19/32 open-end wrench,
stamped "Forged in U.S.A." along a curved arc on one face,
with a "G" code and the model number on the other face.
The overall length is 6.3 inches,
and the finish is plain steel.
The plain finish and stamped "G" code indicate a manufacturing date in 1945.
Duro-Chrome 1027 19/32x11/16 Open-End Wrench
Fig. 298 shows
a Duro-Chrome 1027 19/32x11/16 open-end wrench,
stamped "Duro-Chrome" with "Forged in U.S.A." along a curved arc on one face,
with the model number stamped on the other end.
The overall length is 7.1 inches,
and the finish is chrome plating.
Duro-Chrome 1729 5/8x3/4 Open-End Wrench
Fig. 299 shows
a Duro-Chrome 1729 5/8x3/4 open-end wrench,
stamped "Duro-Chrome" with "Forged in U.S.A." along a curved arc on one face,
with the model number stamped on the other end.
The overall length is 8.3 inches,
and the finish is chrome plating.
Duro-Chrome (X-Circle) 1028-S 5/8x25/32 Open-End Wrench
Fig. 300 shows
a Duro-Chrome 1028-S 5/8x25/32 open-end wrench,
stamped with the
X-Circle logo on the face,
with "Forged in U.S.A." on the back side face.
The overall length is 8.2 inches,
and the finish is plain steel.
Duro-Chrome 1033C 15/16x1 Open-End Wrench
Fig. 301 shows
a Duro-Chrome 1033C 15/16x1 open-end wrench,
stamped "Duro-Chrome" with "Forged in U.S.A." along a curved arc on one face,
with the model number stamped on the other face,
and with the fractional sizes on the back side faces.
The overall length is 10.6 inches,
and the finish is chrome plating.
Duro-Chrome (X-Circle) 1034-A 15/16x1-1/16 Open-End Wrench
Fig. 302 shows
a Duro-Chrome 1034-A 15/16x1-1/16 open-end wrench,
stamped with the X-Circle logo on the face,
with "Forged in U.S.A." on the back side face.
The overall length is 10.5 inches,
and the finish is black oxide.
Tappet Wrenches
The 1935 Duro catalog offered tappet wrenches in six sizes,
D1 (7/16x17/32), D1A (7/16x1/2), D2 (1/2x9/16), D3 (5/8x11/16), D4(3/4x7/8), and D4A (3/4x13/16).
Duro-Chrome D-1 7/16x17/32 Tappet Wrench
Fig. 303 shows
a Duro-Chrome D-1 7/16x17/32 tappet wrench,
stamped "Forged in U.S.A." in a curved arc.
The overall length is 8.0 inches,
and the finish is chrome plating with polished faces.
Duro-Chrome D-2 1/2x9/16 Tappet Wrench
Fig. 304 shows
a Duro-Chrome D-2 1/2x9/16 tappet wrench,
stamped "Forged in U.S.A." in a curved arc.
The overall length is 8.2 inches,
and the finish is chrome plating with polished faces.
Duro-Chrome D-3 5/8x11/16 Tappet Wrench
Fig. 305 shows
a Duro-Chrome D-3 5/8x11/16 tappet wrench,
stamped "Duro-Chrome" with "Forged in U.S.A." in a curved arc on the left face,
with the model number on the right face,
and with the fractional sizes on the back side faces.
The overall length is 9.0 inches.
The original finish was chrome plating,
but most has been lost due to extensive rust.
Duro-Chrome LDT-22 11/16 Long Tappet Wrench
Duro also offered an LDT series of long single-ended tappet wrenches,
as illustrated in the next figure.
Fig. 306 shows
a Duro-Chrome LDT-22 11/16 tappet wrench,
stamped "Duro-Chrome" with "Forged in U.S.A." in a curved arc on the face,
with the model number and fractional size on the back side.
The overall length is 12.3 inches,
and the finish is nickel plating.
Angle-Head Obstruction Wrenches
By 1933 Duro was offering angle-head obstruction wrenches with an interesting design,
using equal openings with one 90 degree offset and one 45 degree offset.
This design is believed to have originated with Herbrand,
and by 1932 Herbrand was supplying "Obstructo" wrenches of this style to Western Auto Supply.
Duro's obstruction wrenches are almost identical copies of the Herbrand counterparts —
even down to the model number —
suggesting that Duro was trying to win more business with Western Auto.
(Duro and Indestro were fiercely competitive in the high-volume low-cost market.)
Duro probably started selling angle-head obstruction wrenches through Western Auto Supply in 1933,
as by this time the catalogs were no longer showing the Herbrand name with the wrenches.
In this same time frame Duro also supplied obstruction wrenches to Sears Roebuck for their
"Cross Country" brand,
and an example can be seen as the
Cross Country 1831 Obstruction Wrench.
Our earliest catalog reference for these wrenches is the 1935 Duro Metal Products catalog.
It lists obstruction wrenches in seven models,
1821 (3/8), 1823 (7/16), 1825 (1/2), 1827 (9/16), 1829 (5/8), 1830 (11/16), and 1831 (3/4).
A set of the seven wrenches in a leatherette roll was available as the No. 18007 set
with a $7.30 list price.
Indestro also offered angle-head obstruction wrenches and (somewhat unusually) used the same model numbers as Duro.
However, for some reason we don't have many examples to show,
so we've lumped the Indestro models together here with Duro.
Duro-Chrome 1821 3/8x3/8 Angle-Head Obstruction Wrench
Fig. 307 shows
a Duro-Chrome 1821 3/8x3/8 obstruction wrench,
stamped "Duro-Chrome" and "Forged in U.S.A." on the face.
The overall length is 5.5 inches,
and the finish is plain steel.
Duro-Chrome 1823 7/16x7/16 Angle-Head Obstruction Wrench
Fig. 308 shows
a Duro-Chrome 1823 7/16x7/16 obstruction wrench,
stamped "Duro-Chrome" and "Forged in U.S.A." on the face.
The overall length is 5.5 inches.
The finish on this wrench is appears to be polished nickel on the faces
with a satin finish on the shank.
Duro-Chrome 1825 1/2x1/2 Angle-Head Obstruction Wrench
Fig. 309 shows
a Duro-Chrome 1825 1/2x1/2 obstruction wrench,
stamped "Duro-Chrome" and "Forged in U.S.A." on the face.
The overall length is 6.5 inches,
and the finish is nickel plating.
Duro-Chrome 1827 9/16x9/16 Angle-Head Obstruction Wrench
Fig. 310 shows
a Duro-Chrome 1827 9/16x9/16 obstruction wrench,
stamped "Duro-Chrome" and "Forged in U.S.A" on the face.
The overall length is 6.5 inches,
and the finish is chrome plating,
with some losses due to wear.
[Indestro] Super-Quality 1827 9/16x9/16 Angle-Head Obstruction Wrenches
The next figures show two examples of the Super-Quality 1827 obstruction wrench,
including one with a less common "Indestro" marking.
Fig. 311 shows
an Indestro Super-Quality 1827 9/16x9/16 obstruction wrench,
stamped "Indestro Mfg. Corp. Chicago" on the shank.
One face is stamped with "Super Quality" and the model number,
with "Chrome Vanadium Steel" in a slanted font on the other end,
and with "Forged in U.S.A." on the back side.
The overall length is 6.5 inches,
and the finish is nickel plating with polished faces.
Fig. 312 shows
a similar Super-Quality 1827 9/16x9/16 obstruction wrench,
but without the Indestro marking.
One face is stamped with "Super Quality" and the model number,
with "Chrome Vanadium Steel" in a slanted font on the other end,
and with "Forged in U.S.A." on the back side.
The overall length is 6.5 inches,
and the finish is nickel plating with polished faces.
Duro-Chrome 1830 11/16x11/16 Angle-Head Obstruction Wrench
Fig. 313 shows
a Duro-Chrome 1830 11/16x11/16 obstruction wrench,
stamped "Forged in U.S.A." in a curved arc on the face.
The overall length is 7.4 inches,
and the finish is chrome plating.
Duro-Chrome 1831 3/4x3/4 Angle-Head Obstruction Wrench
Fig. 314 shows
a Duro-Chrome 1831 3/4x3/4 obstruction wrench,
stamped "Forged in U.S.A." in a curved arc on the face.
The overall length is 7.4 inches,
and the finish is chrome plating.
Ignition Wrenches
Ignition wrenches are a specialized subset of open-end wrenches
designed with small openings and thin heads.
Duro offered ignition wrenches in two styles:
an E6x series with different openings and different offset angles,
and an 8x series with equal-sized openings but different offset angles.
Wrenches in the E6x series were made in model number pairs,
with the same sizes but opposite offset angles.
A review of the Duro catalogs shows that the E6x series wrenches were first offered
sometime after 1935,
with our first reference being the 1938 catalog.
(The 1935 catalog listed wrenches of this design, but in a 176x model number series.)
The 1938 catalog doesn't specify the finish of the wrenches,
suggesting that the wrenches may have had a plain steel finish in the beginning.
One quirk to note is that later catalogs listed the E6x series with just 6x model numbers,
but based on our observations the actual markings include the leading "E".
The 8x series ignition wrenches were first offered in the mid 1940s,
with the 1946 Duro catalog providing our earliest reference.
By 1955 the 8x series was no longer listed in the Duro catalog and presumably had been discontinued.
In the immediate post-war period the finish for both styles was still unspecified,
but by 1955 the 6x series were listed with chrome plated finishes and polished faces.
Duro-Chrome E61 13/64x15/64 Ignition Wrench
The next figures show examples of the E61/E62 pair of 13/16x15/16 ignition wrenches.
Fig. 315 shows
a Duro-Chrome E61 13/64x15/64 ignition wrench,
stamped with "USA" (clipped) and "Duro-Chrome" along a curved arc on the face.
The overall length is 3.0 inches,
and the finish is plain steel.
In this model the smaller opening is at the less offset end.
The matching wrench with opposite offsets is the E62 model.
Duro-Chrome E62 13/64x15/64 Ignition Wrench
Fig. 316 shows
a Duro-Chrome E62 13/64x15/64 ignition wrench,
stamped with "U.S.A." and "Duro-Chrome" along a curved arc on the face.
The overall length is 3.0 inches,
and the finish is chrome plating with polished faces.
In this model the larger opening is at the less offset end.
The matching wrench with opposite offsets is the E61 model.
Duro-Chrome E63 7/32x1/4 Ignition Wrench
Fig. 317 shows
a Duro-Chrome E63 7/32x1/4 ignition wrench,
stamped with "U.S.A." and "Duro-Chrome" along a curved arc on the face.
The overall length is 3.0 inches,
and the finish is chrome plating with polished faces.
In this model the smaller opening is at the less offset end.
The matching wrench with opposite offsets is the E64 model.
Duro-Chrome E65 9/32x5/16 Ignition Wrench
Fig. 318 shows
a Duro-Chrome E65 9/32x5/16 ignition wrench,
stamped "USA" with "Duro Chrome" along a curved arc on the face.
The overall length is 3.5 inches,
and the finish is plain steel.
In this model the smaller opening is at the less offset end.
The matching wrench with opposite offsets is the E66 model.
Duro-Chrome E67 11/32x3/8 Ignition Wrench
The next two figures show a matched pair of E67/E68 wrenches in the 11/32x3/8 size.
Fig. 319 shows
a Duro-Chrome E67 11/32x3/8 ignition wrench,
stamped "U.S.A." with "Duro-Chrome" in a curved arc on the face.
The overall length is 4.0 inches,
and the finish is plain steel.
In this model the smaller opening is at the less offset end.
The matching wrench with opposite offsets is the E68 model.
Duro-Chrome E68 11/32x3/8 Ignition Wrench
Fig. 320 shows
a Duro-Chrome E68 11/32x3/8 ignition wrench,
stamped "U.S.A." with "Duro-Chrome" in a curved arc on the face.
The overall length is 4.0 inches,
and the finish is plain steel.
In this model the larger opening is at the less offset end.
The matching wrench with opposite offsets is the E67 model.
Duro-Chrome E69 7/16x1/2 Ignition Wrench
Fig. 321 shows
a Duro-Chrome E69 7/16x1/2 ignition wrench,
stamped "U.S.A." with "Duro-Chrome" in a curved arc on the face.
The overall length is 4.5 inches,
and the finish is plain steel.
In this model the smaller opening is at the less offset end.
The E69 model was the largest of the E6x series,
and for some reason Duro didn't make the matching wrench (i.e. with different offset angles)
for this size.
Duro-Chrome 81 7/32x7/32 Ignition Wrench
In later years the 8x series of ignition wrenches were finished with chrome plating and polished faces,
as the next several figures show.
Fig. 322 shows
a Duro-Chrome 81 7/32x7/32 ignition wrench,
stamped "USA" with "Duro Chrome" in a curved arc on the face.
The overall length is 3.1 inches,
and the finish is chrome plating.
Duro-Chrome 82 15/64x15/64 Ignition Wrench
Fig. 323 shows
a Duro-Chrome 82 15/64x15/64 ignition wrench,
stamped "USA" with "Duro-Chrome" in a curved arc on the face.
The overall length is 3.1 inches,
and the finish is chrome plating.
Duro-Chrome 83 1/4x1/4 Ignition Wrench
Fig. 324 shows
a Duro-Chrome 83 1/4x1/4 ignition wrench,
stamped "USA" with "Duro-Chrome" in a curved arc on the face.
The overall length is 3.1 inches,
and the finish is chrome plating.
Duro-Chrome 86 11/32x11/32 Ignition Wrench
Fig. 325 shows
a Duro-Chrome 86 11/32x11/32 ignition wrench,
stamped "U.S.A." with "Duro-Chrome" in a curved arc on the face.
The overall length is 3.9 inches,
and the finish is plain steel.
Duro-Chrome 88 7/16x7/16 Ignition Wrench
Fig. 326 shows
a Duro-Chrome 88 7/16x7/16 ignition wrench,
stamped "U.S.A." with "Duro-Chrome" in a curved arc on the face.
The overall length is 4.5 inches,
and the finish is plain steel.
Combination Wrenches
By 1935 Duro had introduced the Duro-Chrome 020xx series of combination wrenches.
The combination style with open and box ends of equal size was still quite new at the time,
as it had been first offered only in April of 1933 by Plomb and soon afterwards by Bonney.
Even the name "combination" was not yet universally accepted,
with other companies using terms like "TuType", "Multitype", or even "Half & Half"!
(See our section on Plomb Combination Wrenches
for some background information on this important style.)
Duro's initial design had a very thin open end with a flat shank and a small round box end,
which was rather different from what other companies considered as "combination" wrenches.
Instead of being conceptually a standard open-end and box-end joined together,
Duro in effect was offering a combination tappet wrench.
This thin style is illustrated in the 1935, 1938, and 1939 Duro-Chrome catalogs.
The 020xx Thin Series
The scan in Fig. 327 shows an early (possibly the first) listing for the 020xx series combination wrenches,
as published on page 7 of the 1935 Duro catalog.
Note that there is no mention of the very thin design,
other than a cryptic mention of "work in difficult places".
For Duro a leading "0" in a model number is usually associated with tools marked for the Handy-Hex brand,
and the page with the combination wrenches has a heading "Handy-Twin-Hex".
However, our examples with a leading "0" model number are marked for Duro-Chrome.
The Duro 020xx series was also offered as the Indestro 77x series,
which the 1935 Indestro catalog referred to as "2-Way Box End Wrenches".
The catalog specifications show the same sizes and lengths as the Duro listing above.
The Expanded 20xx Thin Series
By 1938 Duro had significantly expanded their selection of combination wrenches by extending the series
and adding some intermediate sizes.
In addition, the leading "0" of the model numbers had been dropped.
The new sizes were model 2034A (19/32), 2037 (3/4), 2037A (25/32), 2038 (7/8), and 2039 (15/16).
The 1938 catalog noted that the wrenches were drop forged from chrome vanadium steel and had
triple plated finishes with polished heads.
However, there was still no mention of the very thin construction.
The "Dart" Design
By 1941 Duro had redesigned its combination wrenches to include a paneled shank with rounded edges,
plus a distinctive "dart" design at the open end.
This new design took over the 20xx model series and remained in production until the early 1960s.
In the "Dart" design the thickness of the open end was increased to about the same as a standard open-end wrench,
thereby fixing the main problem with the original thin wrenches.
The shank of the "Dart" wrenches was still quite thin,
but it included rounded ribs on both edges that would have substantially increased the strength.
The "Dart" series can be considered as Duro's entry for the "standard" combination wrench,
offering the expected strength along with the company's industrial design aesthetic.
The 22xx Thin Series
With the introduction of the "Dart" style,
Duro began a second 22xx series of combination wrench models with the same extra-thin heads
and flat shanks as the original [0]20xx models.
But this time the wrenches were at least labeled as "Thin Pattern",
and the description noted that they were intended for work in restricted spaces.
The scan in Fig. 328 shows a listing for the 22xx series of thin combination wrenches,
as published on page 45 of the 1946 Duro catalog.
The text notes the construction from chrome alloy steel and the design for work in restricted spaces.
The catalog table unfortunately does not specify the thickness of the heads,
but we believe the wrenches at this time would be the same as the examples shown below.
The 22xx Thicker Thin Wrenches
By 1951 (Duro catalog No. 35) the 22xx series had undergone a stealth change.
Although still billed as "Thin Pattern" combination wrenches,
the head thickness had been increased substantially,
and was now only slightly thinner than the "Dart" style wrenches.
The scan in Fig. 329 shows a listing for the 22xx series of thin combination wrenches,
as published on page 31 of the 1951 Duro catalog No. 35.
(This catalog is available for
Download
[External Link] from the ITCL.)
Note that the catalog listing now includes a column specifying the head thickness,
and the specified thickness values are substantially greater than
what we measured for the earlier generation wrenches.
For example,
in 1951 the model 2233 (1/2) wrench had a specified head thickness of 7/32 or approximately 0.22 inches,
compared with the measured 0.18 thickness of our earlier example.
(See the
Duro 2233 1/2 Thin Combination Wrench below.)
The corresponding "Dart" style 1/2 wrench had a specified thickness of 15/64,
only 1/64 thicker than the "thin" model!
From this we can see that by 1951 Duro had hedged their bets on the concept of "thin" combination wrenches.
Late Combination Wrenches
By 1961 (Duro catalog No. 37) the 22xx series wrenches were no longer being called "thin" and were offered as
Duro's standard-duty combination wrenches.
By this time an additional series of short combination wrenches had been added,
which were identified by an "S" suffix and were available in sizes from 2227S (1/4) up to 2237S (3/4).
The catalog listings for both standard and short models included a column with the head thickness,
and interestingly enough,
the short series wrenches had slightly thicker heads (by 1/64 of an inch) than the corresponding standard model.
The specified head thicknesses for the standard models in 1961 were similar to those published in the 1951 catalog,
but a few models had slightly thicker or thinner heads.
These later 22xx series wrenches are competently made but fairly generic in appearance,
and lack the stylish touches that made earlier Duro/Indestro tools stand out.
The 20xx "Dart" style wrenches were still available in 1961 but were discontinued somewhat later.
One last change to note is that by around 1972 the 22xx combination wrenches had been superseded by a 33xx series,
with sizes ranging from model 3312 (3/8) up to 3364 (2 inches),
and with the last digits of the model number indicating the opening size in 32nds.
By this time we trust that our readers are as confused as we are by the saga of the Duro combination wrench,
and important questions such as "Why did they make the extra thin combination wrenches in the first place?"
or "Why couldn't the dart style get the 22xx model numbers?" will go forever unanswered.
In this section we'll look at earlier examples of the various combination wrench models,
with production from the mid 1930s up to the late 1940s.
Later examples can be seen in the section on
Late Combination Wrenches.
Early Thin-Style Combination Wrenches
We'll begin with some very early examples of the Duro-Chrome combination wrench series,
as indicated by the leading "0" of the model number.
The 1935 catalog first listed combination wrenches as the 020xx series,
but by 1938 the series were listed with 20xx model numbers.
Early Duro-Chrome 02032 7/16 Thin Combination Wrench
Fig. 330 shows
a Duro-Chrome 02032 7/16 combination wrench with a flat shank,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 7.2 inches,
and the head thickness was measured at 0.16 inches.
The wrench has a triple-plated finish with polished chrome on the faces and box end
and a satin finish on the shank.
The top inset shows a side view of the wrench,
illustrating the very thin profile of this early model.
The leading "0" of the model number indicates a production date prior to 1938 for this example,
as the 1938 catalog lists these wrenches in a 20xx series.
Early Duro-Chrome 02033 1/2 Thin Combination Wrench
Fig. 331 shows
a Duro-Chrome 02033 1/2 combination wrench with a flat shank,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 7.5 inches,
and the head thickness was measured at 0.16 inches.
The wrench has a triple-plated finish with polished chrome on the faces and box end
and a satin finish on the shank.
The top inset shows a side view of the wrench,
illustrating the very thin profile of this early model.
The leading "0" of the model number indicates a production date prior to 1938 for this example,
as the 1938 catalog lists these wrenches in a 20xx series.
Early Duro-Chrome 02035 5/8 Thin Combination Wrench
Fig. 332 shows
a Duro-Chrome 02035 5/8 combination wrench with a flat shank,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 8.3 inches,
and the head thickness was measured at 0.18 inches.
The wrench has a triple-plated finish with polished chrome on the faces and box end
and a satin finish on the shank.
The top inset shows a side view of the wrench,
illustrating the very thin profile of this early model.
The leading "0" of the model number indicates a production date prior to 1938 for this example,
as the 1938 catalog lists these wrenches in a 20xx series.
Early Duro-Chrome 02036 11/16 Thin Combination Wrench
Fig. 333 shows
a Duro-Chrome 02036 11/16 combination wrench with a flat shank,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 8.6 inches,
and the head thickness was measured at 0.19 inches.
The wrench has a triple-plated finish with polished chrome on the faces and box end
and a satin finish on the shank.
The top inset shows a side view of the wrench,
illustrating the very thin profile of this early model.
The leading "0" of the model number indicates a production date prior to 1938 for this example,
as the 1938 catalog lists these wrenches in a 20xx series.
Later Thin-Style Combination Wrenches
The next several figures show examples of Duro's thin combination wrenches in the later 22xx model series.
These wrenches were produced from around 1941-1950,
after which they were superseded by wrenches of intermediate thickness bearing the same model numbers.
Examples of the later 22xx series with standard dimensions can be seen in the section on
Late Combination Wrenches.
[Duro-Chrome] 2233 1/2 Thin Combination Wrenches
The next two figures show examples of the Duro-Chrome 2333 thin combination wrench.
Fig. 334A shows
a Duro-Chrome 2233 1/2 thin combination wrench,
stamped "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 7.7 inches,
and the thickness was measured at 0.18 inches.
The top inset shows a side view of the wrench,
illustrating the very thin profile of this model.
The finish is black oxide augmented with natural rust.
This wrench isn't marked with the brand name,
but can be identified by the model number and construction,
and by the "Forged in U.S.A." marking along a curved arc.
The plain or oxide finish and absence of a marked brand name indicates production during the 1942-1945 wartime years.
Fig. 334B shows
another example of the Duro-Chrome 2233 1/2 thin combination wrench,
stamped "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 7.7 inches,
and the thickness was measured at 0.19 inches.
The finish is plain steel.
This example isn't marked with the brand name,
but can be identified by the model number and construction,
and by the "Forged in U.S.A." marking along a curved arc.
The plain finish and absence of a marked brand name indicates production during the 1942-1945 wartime years.
Duro-Chrome 2234 9/16 Thin Combination Wrench
Fig. 335 shows
a Duro-Chrome 2234 9/16 combination wrench,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 8.2 inches,
and the head thickness was measured at 0.19 inches.
The finish is chrome plating,
with extensive losses due to wear.
The top inset illustrates the thin profile of this model series.
[Duro-Chrome] 2236 11/16 Thin Combination Wrench
Fig. 336 shows
a Duro-Chrome 2236 11/16 combination wrench,
stamped "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 9.4 inches,
and the head thickness was measured at 0.20 inches.
The finish is plain steel.
The top inset shows the very thin profile of this wrench,
comparable to that of a tappet wrench.
This wrench isn't marked with a brand name,
but can be identified by the model number and construction,
and by the "Forged in U.S.A." marking along a curved arc.
The plain finish and absence of a marked brand name indicates production during the 1942-1945 wartime years.
[Duro-Chrome 2239] 15/16 Thin Combination Wrench
Fig. 336B shows
a Duro-Chrome 2239 15/16 combination wrench,
stamped "Forged in U.S.A." along a curved arc on the front face,
with the fractional size on the back face.
The overall length is 11.9 inches,
and the head thickness was measured at 0.25 inches.
The finish is plain steel with extensive rust and pitting.
The top inset shows the very thin profile of this wrench,
comparable to that of a tappet wrench.
This wrench isn't marked with a brand name,
but can be identified by its thin construction and the "Forged in U.S.A." marking along a curved arc.
The plain finish and absence of a marked brand name indicates production during the 1942-1945 wartime years.
Dart-Style Combination Wrenches
The next several figures show examples of "Dart" style combination wrenches,
which were assigned 20xx model numbers previously used for the early thin-format wrenches.
The "Dart" wrenches were produced from around 1941 until the 1960s.
Duro-Chrome "Dart" 2031 3/8 Combination Wrench
Fig. 338 shows
a Duro-Chrome 2031 3/8 combination wrench in the "Dart" style,
stamped with Duro-Chrome and "Forged in U.S.A." along a curved arc on the face,
with a distinctive streamlined dart emanating from the head.
The overall length is 7.3 inches,
and the finish is cadmium plating.
The cadmium finish suggests production during the wartime years.
Duro-Chrome "Dart" 2035 5/8 Combination Wrenches
The next figures show two generations of the Duro-Chrome 2035 wrench.
Fig. 339A shows
an early Duro-Chrome 2035 5/8 combination wrench in the "Dart" style,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 8.8 inches,
and the finish is plain steel with traces of chrome plating.
The traces of plated finish suggest production during the early wartime years.
Fig. 339B shows
a somewhat later Duro-Chrome 2035 5/8 combination wrench in the "Dart" style,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 8.9 inches,
and the finish is chrome plating with polished faces.
The chrome finish on this wrench suggests production from the post-war era into the early 1960s.
Duro-Chrome "Dart" 2036 11/16 Combination Wrench
Fig. 339B shows
a Duro-Chrome 2036 11/16 combination wrench in the "Dart" style,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 9.3 inches,
and the finish is plain steel with polished faces.
The plain finish suggests production during the wartime years.
Duro-Chrome "Dart" 2037 3/4 Combination Wrench
Fig. 340 shows
a Duro-Chrome 2037 3/4 combination wrench in the "Dart" style,
stamped with "Duro-Chrome" and "Forged in U.S.A." along a curved arc on the face.
The overall length is 10.2 inches,
and the finish is cadmium plating.
The cadmium finish suggests production during the wartime years.
This wrench is a good example of the curved "Forged in U.S.A." marking used on Duro and Indestro tools.
[Duro-Chrome] "Dart" 2039 15/16 Combination Wrench
Fig. 341 shows
a Duro-Chrome 2039 15/16 combination wrench in the "Dart" style,
stamped with "Forged in U.S.A." along a curved arc on the front face,
with the model number and fractional size on the back face.
The overall length is 10.2 inches,
and the finish is plain steel.
This wrench is not marked with the brand name,
but is easily identified by the distinctive "Dart" style and "Forged in U.S.A." marking
along a curved arc.
The plain steel finish and absence of a marked brand name indicates production during the 1942-1945 wartime years.
Box-End Wrenches
Duro's earliest box-end wrench production is believed to have been the "Perfection" brand wrenches
sold through Western Auto Supply beginning in 1932.
These wrenches were developed as copies of the Herbrand "Multihex" wrenches first offered by
Western Auto in 1931.
Duro's own production initially used the Handy-Hex brand.
Our first catalog reference for box-end wrenches is the 1935 Duro catalog,
which lists box wrenches in four basic styles under a "Handy-Twin-Hex" heading.
All of the wrenches have a five-digit model number with a leading "0",
which match the model numbers of the known Handy-Hex wrenches.
This strongly suggests that all of the box wrenches were being marked with the Handy-Hex brand at this time.
Our next catalog reference is the 1938 Duro catalog,
and by this time the box wrenches are listed under a Duro-Chrome heading and are illustrated with
streamlined panels.
In addition, the wrenches now have the Duro standard four-digit model numbers without the leading zero.
Since the catalogs suggest a change to the Duro-Chrome brand around the advent of the
streamlined panel design,
we checked our substantial inventory of Duro-Chrome wrenches for confirmation.
Based on our inventory,
we found that the Duro-Chrome marking occurs only on wrenches with the streamlined panel design,
except for a few specialty wrenches that were never produced with the streamlined design.
Conversely, no wrenches in the streamlined panel design have been found marked for Handy-Hex,
except when also marked for Duro-Chrome.
Based on the catalog information and empirical evidence,
we believe that Duro used the Handy-Hex brand exclusively for box wrenches up until about 1937,
and then switched to the Duro-Chrome brand for the subsequent production with streamlined panels.
(The occasional Duro-Chrome and Handy-Hex dual markings were probably done to provide continuity
with the older brand.)
With this information we can estimate the production dates for Handy-Hex tools as the early 1930s to 1936.
As with the Indestro box wrenches,
the Duro wrenches were available in four basic styles with a wide range of sizes.
And once again,
the box wrenches received ad hoc model numbers,
not derived from industry-standard numbers,
and not matching the Indestro models.
Offset Box-End Wrenches
In 1935 Duro's offset box-end wrenches were available in nine sizes,
with models 02051 (3/8x7/16), 02052 (1/2x9/16), 02053 (5/8x11/16), 02054 (3/4x25/32), 02055 (13/16x7/8),
02056 (15/16x 1 inch), 02057 (1-1/16x1-1/8), 02058A (1-3/16x1-1/4), and 02058B (1-1/8x1-1/4).
The model numbers with a leading "0" correspond to the Handy-Hex brand,
and the later Duro-Chrome tools used the same numbers without the leading "0".
In later years some additional sizes were available.
Handy-Hex 02051 3/8x7/16 Offset Box-End Wrench
Fig. 342 shows
a Handy-Hex 02051 3/8x7/16 offset box-end wrench,
stamped with "Chrome Vanadium Steel" and the fractional sizes on the shank,
with "Handy-Hex" and "Made in U.S.A." on the back side.
The overall length is 7.8 inches,
and the finish appears to be nickel plating.
The top inset shows a side view of the wrench,
illustrating the deep offset profile of this design.
Handy-Hex 02052 1/2x9/16 Offset Box-End Wrench
Fig. 343 shows
a Handy-Hex 02052 1/2x9/16 offset box-end wrench,
stamped with "Chrome Vanadium Steel" and the fractional sizes on the shank,
with "Handy-Hex" and "Made in U.S.A." on the back side.
The overall length is 8.8 inches.
The finish is plain steel,
with possible traces of a plated finish.
The top inset shows a side view of the wrench,
illustrating the deep offset profile of this design.
Duro-Chrome 2052A 9/16x5/8 Offset Box Wrench
Fig. 344 shows
a later Duro-Chrome 2052A 9/16x5/8 offset box wrench with streamlined raised panels,
stamped with "Duro-Chrome" and the model number
on the front panel,
with "Forged in U.S.A." and the fractional sizes on the back side panel.
The overall length is 9.5 inches,
and the finish is chrome plating.
The lack of an alloy steel specification indicates a post-war production date for this example.
Handy-Hex 02053 5/8x11/16 Offset Box-End Wrench
The next several figures show two generations of the 02053/2053 5/8x11/16 wrench model,
with differences in the brand marking and finish.
Fig. 345 shows
an earlier Handy-Hex 02053 5/8x11/16 offset box-end wrench,
stamped with the fractional sizes and "Chrome Vanadium Steel" on one side,
with "Handy-Hex" and "Made in U.S.A." on the back side.
The overall length is 9.9 inches.
The finish is chrome plating with polished ends,
with some losses due to wear and corrosion.
The top inset shows a side view of the wrench,
illustrating the deep offset profile of this design.
Fig. 346 shows
another Handy-Hex 02053 5/8x11/16 offset box-end wrench,
stamped with the fractional sizes and "Chrome Vanadium Steel" on one side,
with "Handy-Hex" and "Made in U.S.A." on the back side.
The overall length is 10.2 inches,
and the finish is plain steel.
Duro-Chrome (X-Circle) 2053 5/8x11/16 Offset Box Wrench
Fig. 347 shows
a later Duro-Chrome 2053 5/8x11/16 offset box wrench with streamlined raised panels,
stamped with "Duro-Chrome" and the
X-Circle logo on the front panel,
with "Forged in U.S.A." and the fractional sizes on the back side.
The overall length is 10.0 inches,
and the finish is black oxide augmented by rust.
The lack of the "Chrome Vanadium Steel" marking and use of the X-Circle logo suggest production
in the later 1943-1945 wartime years.
Handy-Hex 02054 3/4x25/32 Offset Box-End Wrenches
The next several figures show examples of the 02054/2054 3/4x25/32 wrench model,
with differences in the brand marking and finish.
Fig. 348 shows
an earlier Handy-Hex 02054 3/4x25/32 offset box-end wrench,
marked "Made in U.S.A." with "Chrome Vanadium Steel" on the back side.
The overall length is 11.3 inches,
and the finish is plain steel.
The top inset shows a side view of the wrench,
illustrating the deep offset profile of this design.
Fig. 349 shows
another Handy-Hex 02054 3/4x25/32 offset box-end wrench,
stamped with "Chrome Vanadium Steel" and the fractional sizes on the shank,
with "Handy-Hex" and "Made in U.S.A." on the back side.
The overall length is 11.3 inches,
and the finish is chrome plating with polished box ends.
The top inset shows a side view of the wrench,
illustrating the deep offset profile of this design.
Duro-Chrome 2054 3/4x25/32 Offset Box Wrench
Fig. 350 shows
a later Duro-Chrome 2054 3/4x25/32 offset box wrench with streamlined raised panels,
stamped "Duro-Chrome" and "Forged in U.S.A." on the front panel,
with "Chrome Vanadium Steel" and the fractional sizes on the back side.
The overall length is 11.3 inches,
and the finish is chrome plating.
An earlier version of this model can be seen as the
Handy-Hex 02054 Offset Box Wrench.
Handy-Hex 02055 13/16x7/8 Offset Box Wrench
The next figures show two generations of the 02055/2055 13/16x7/8 wrench model,
with differences in the brand marking and finish.
Fig. 351 shows
an earlier Handy-Hex 02055 13/16x7/8 offset box wrench,
stamped with "Handy-Hex" and "Made in U.S.A." on the shank,
with "Chrome Vanadium Steel" and the fractional sizes on the back side.
The overall length is 12.7 inches,
and the finish is nickel plating,
with losses due to wear and rust.
The markings on this wrench are upside-down when the wrench is turned over,
unlike most of the other Handy-Hex examples.
Duro-Chrome 2055 13/16x7/8 Offset Box Wrench
Fig. 352 shows
a later Duro-Chrome 2055 13/16x7/8 offset box wrench with streamlined raised panels,
stamped with "Duro-Chrome" and the fractional sizes on the front panel,
with "Forged in U.S.A." and the model number on the back side.
The overall length is 12.8 inches,
and the finish is chrome plating.
The lack of an alloy steel marking on this example suggests production in the post-war period.
Handy-Hex 02056 15/16x1 Offset Box-End Wrench
Fig. 353 shows
a Handy-Hex 02056 15/16x1 offset box-end wrench,
stamped with "Chrome Vanadium Steel" and the fractional sizes on the shank,
with "Handy-Hex" and "Made in U.S.A." on the back side.
The overall length is 14.4 inches,
and the finish is chrome plating,
with some losses due to rust.
The top inset shows a side view of the wrench,
illustrating the deep offset profile of this design.
Duro-Chrome (X-Circle) 2056 15/16x1 Offset Box Wrench
Fig. 354 shows
a Duro-Chrome 2056 15/16x1 offset box wrench with streamlined raised panels,
stamped with "Forged in U.S.A." and the fractional sizes on the front panel,
with "Duro-Chrome" and the
X-Circle logo on the back side panel.
The overall length is 14.5 inches,
and the finish is plain steel.
The lack of the "Chrome Vanadium Steel" marking and use of the X-Circle logo suggest production
in the later 1943-1945 wartime years.
Duro-Chrome 2057 1-1/16x1-1/8 Offset Box Wrench
Fig. 355 shows
a Duro-Chrome 2057 1-1/16x1-1/8 offset box wrench with streamlined raised panels,
stamped with "Chrome Vanadium Steel" and the fractional sizes on the front panel,
with "Duro-Chrome" and "Forged in U.S.A." on the back side panel.
The overall length is 16.4 inches,
and the finish is chrome plating steel.
The streamlined panels, chrome finish, and "Chrome Vanadium Steel" marking indicate production
from 1937 to the early 1940s.
Duro-Chrome (X-Circle) 2058A 1-3/16x1-1/4 Offset Box Wrench
Fig. 356 shows
a Duro-Chrome 2058A 1-3/16x1-1/4 offset box wrench with streamlined raised panels,
stamped with "Duro-Chrome" and the
X-Circle logo on the front panel,
with "Forged in U.S.A." and the fractional sizes on the back side.
The overall length is 18.0 inches,
and the finish is cadmium plating.
The lack of the "Chrome Vanadium Steel" marking and use of the X-Circle logo suggest production
in the later 1943-1945 wartime years.
Note also the somewhat poorly trimmed edges visible in the top inset,
another indication of wartime production.
Duro-Chrome (X-Circle) 2058B 1-1/8x1-1/4 Offset Box Wrench
Fig. 357 shows
a Duro-Chrome 2058B 1-1/8x1-1/4 offset box wrench with streamlined raised panels,
stamped with "Duro-Chrome" and the
X-Circle logo on the front panel,
with "Forged in U.S.A." and the fractional sizes on the back side.
The overall length is 18.2 inches,
and the finish is plain steel.
The lack of the "Chrome Vanadium Steel" marking and use of the X-Circle logo suggest production
in the later 1943-1945 wartime years.
Duro-Chrome "Handy-Hex" 2059A 1-5/16x1-3/8 Offset Box Wrench
Fig. 358 shows
one of the larger Duro-Chrome box wrenches,
a Duro-Chrome 2059A 1-5/16x1-3/8 offset box wrench with streamlined raised panels.
The wrench is dual-marked with "Duro-Chrome" and "Handy-Hex" stamped on the front panel,
with "Chrome Vanadium Steel" and the fractional sizes on the back side.
The overall length is 20.3 inches.
The original finish was chrome plating,
but most has been lost due to rust.
Short Offset Box-End Wrenches
Duro offered short offset box wrenches in four sizes in a 204x model series.
The models and sizes were 2041 (3/8x7/16), 2042 (1/2x9/16), 2043 (5/8x11/16), and 2044 (3/4x25/32).
Although these wrenches were available during the Handy-Hex era,
they appear to be uncommon,
and we don't have any examples to show.
Duro-Chrome 2041 3/8x7/16 Short Offset Box Wrench
Fig. 359 shows
a Duro-Chrome 2041 3/8x7/16 short offset box wrench,
stamped with "Duro-Chrome" and the model number on the streamlined raised panel,
with "Forged in U.S.A." and the fractional sizes on the back side panel.
Note also the stamped "G" and "A" codes in front of the model number.
The overall length is 5.6 inches,
and the finish is plain steel or black oxide.
The plain steel or black oxide finish would suggest a manufacturing date during 1942-1945,
but the "G" code stamped on the panel indicates a more precise 1945 date.
The "G" code indicates manufacture in 1945 under restrictive government regulations,
and can be found occasionally on tools of this era.
(The use of the "G" date code by Snap-on is well documented.)
The meaning of the "A" code is not known.
Duro-Chrome 2042 1/2x9/16 Short Offset Box Wrenches
The next figures show two generations of the 2042 short offset box wrench.
Fig. 360 shows
an earlier Duro-Chrome 2042 1/2x9/16 short offset box wrench,
stamped with "Chrome Vanadium Steel" and the fractional sizes on the streamlined raised panel.
The back side panel is stamped with the "2042" model number between "Duro-Chrome" and "Forged in U.S.A.",
but is difficult to read due to pitting.
The overall length is 5.6 inches.
The finish is plain steel with extensive pitting due to rust,
possibly with traces of a prior plated finish.
Fig. 361 shows
a later Duro-Chrome 2042 1/2x9/16 short offset box wrench,
stamped "Duro-Chrome" with the model number on the streamlined raised panel,
with "Forged in U.S.A." and the fractional sizes on the back side.
Note also the stamped "G" code in front of the model number.
The overall length is 5.2 inches,
and the finish is black oxide.
The black oxide finish would suggest a manufacturing date during 1942-1945,
but the "G" code stamped on the panel indicates a more precise 1945 date.
The "G" code indicates manufacture in 1945 under restrictive government regulations,
and can be found occasionally on tools of this era.
(The use of the "G" date code by Snap-on is well documented.)
Duro-Chrome 2043 5/8x11/16 Short Offset Box Wrench
Fig. 362 shows
a later Duro-Chrome 2043 5/8x11/16 short offset box wrench with raised streamlined panels,
stamped with "Duro Chrome" and the fractional sizes on the front panel,
with the model number and "Forged in U.S.A." on the back side panel.
The overall length is 6.3 inches,
and the finish is chrome plating with polished faces.
The markings on this wrench differ from earlier examples in that the fractional sizes are placed
on the panel with the Duro-Chrome brand,
with the model number on the back side.
Duro-Chrome 2044 3/4x25/32 Short Offset Box Wrench
Fig. 363 shows
a Duro-Chrome 2044 3/4x25/32 short offset box wrench with raised streamlined panels,
stamped with "Chrome Vanadium Steel" and the fractional sizes on the front panel,
with "Duro Chrome" and "Forged in U.S.A." on the back side panel.
The overall length is 7.0 inches,
and the finish is chrome plating,
with some losses due to rust.
Angled Box-End Wrenches
In 1935 angled box-end wrenches were available in five sizes,
with models 02011 (3/8x7/6), 02012 (1/2x9/16), 02013 (9/16x5/8), 02014 (11/16x25/32), and 02015 (3/4x7/8).
Duro-Chrome "G" 2011 3/8x7/16 Box-End Wrench
Fig. 364 shows
a Duro-Chrome 2011 3/8x7/16 box-end wrench,
stamped with the Duro-Chrome trademark and a "G" code on the streamlined raised panel,
with "Forged in U.S.A." on the back side panel.
The overall length is 6.8 inches,
and the finish is plain steel.
The stamped "G" code and plain finish indicate a wartime production date in 1945.
Duro-Chrome 2013 9/16x5/8 Box-End Wrenches
The next figures show two generations of the Duro-Chrome 2013 box wrench.
Fig. 365 shows
an earlier Duro-Chrome 2013 9/16x5/8 box-end wrench with streamlined raised panels,
stamped "Duro-Chrome" and "Forged in U.S.A." on the front panel,
with "Chrome Vanadium Steel" on the back side.
The overall length is 9.0 inches,
and the finish is chrome plating with polished ends.
Fig. 366 shows
a later Duro-Chrome 2013 9/16x5/8 box-end wrench with streamlined raised panels,
stamped with "Duro-Chrome" and the
X-Circle logo on the front panel,
with "Forged in U.S.A." and the fractional sizes on the back side panel.
The overall length is 9.0 inches,
and the finish is plain steel.
The Indestro equivalent of this model can be seen as the
Super-Quality 713 Box Wrench.
Duro-Chrome "G" 2014A 11/16x3/4 Box-End Wrench
Fig. 367 shows
a Duro-Chrome 2014A 11/16x3/4 box-end wrench with streamlined raised panels,
stamped with "Duro-Chrome" and a "G" code on the front panel,
with "Forged in U.S.A." and the fractional sizes on the back side.
The overall length is 10.3 inches,
and the finish is plain steel or black oxide.
The stamped "G" code and plain finish indicate a wartime production date in 1945.
Duro-Chrome 2014 11/16x25/32 Box-End Wrench
Fig. 368 shows
a Duro-Chrome 2014 11/16x25/32 box-end wrench with streamlined raised panels,
stamped "Duro-Chrome" and "Forged in U.S.A." on the front panel,
with "Chrome Vanadium Steel" and the fractional sizes on the back side.
The overall length is 10.1 inches,
and the finish is chrome plating with polished ends.
Duro-Chrome 2015 3/4x7/8 Box-End Wrenches
The next two figures show examples of the Duro-Chrome 2015 wrench,
both from wartime production but with interesting differences in construction and marking.
Fig. 369 shows
a Duro-Chrome 2015 3/4x7/8 box-end wrench with raised streamlined panels,
stamped "Duro-Chrome" and "Forged in U.S.A." on the front panel,
with "Chrome Vanadium Steel" and the fractional sizes on the back side panel.
The overall length is 11.1 inches,
and the finish is plain steel.
The plain finish suggests production during the wartime years,
and the "Chrome Vanadium Steel" marking suggests the earlier 1941-1942 period.
Except for the plain finish,
this wrench would be typical of Duro's production in the late 1930s to early 1940s.
Fig. 370 shows
a Duro-Chrome 2015 3/4x7/8 box-end wrench with raised parallelogram panels,
stamped "Duro-Chrome" and "Forged in U.S.A." on the front panel,
with "Chrome Vanadium Steel" and the fractional sizes on the back side panel.
The overall length is 11.1 inches,
and the finish is plain steel.
The plain finish and the use of parallelogram panels on a Duro-marked tool suggest production
during the wartime years,
and the "Chrome Vanadium Steel" marking suggests the earlier 1941-1942 period.
Duro-Chrome (X-Circle) 2015A 13/16x7/8 Box-End Wrench
Fig. 371 shows
a Duro-Chrome 2015A 13/16x7/8 box-end wrench with streamlined panels,
stamped with "Duro-Chrome" and the
X-Circle logo on the front panel,
with "Forged in U.S.A." and the fractional sizes on the back side panel.
The overall length is 11.3 inches,
and the finish is plain steel.
The lack of the "Chrome Vanadium Steel" marking and use of the X-Circle logo suggest production
in the later 1943-1945 wartime years.
Duro-Chrome 2017 1-1/16x1-1/8 Box-End Wrench
Fig. 372 shows
a Duro-Chrome 2017 1-1/16x1-1/8 box-end wrench with streamlined panels,
stamped "Duro-Chrome" and "Forged in U.S.A." on the raised panel,
with "Chrome Vanadium Steel" and the fractional sizes on the back side.
The overall length is 17.7 inches,
and the finish is plain steel.
The plain finish suggests production in the early wartime years.
Short Angled Box-End Wrenches
Duro-Chrome offered short angled (15 degree) box wrenches in a 206x model series.
The models and sizes were 2061 (3/8x7/16), 2062 (1/2x9/16), 2063 (5/8x11/16), and 2064 (3/4x25/32).
Duro-Chrome 2061 3/8x7/16 Short Box-End Wrench
Fig. 373 shows
a Duro-Chrome 2061 3/8x7/16 box wrench,
stamped "Duro-Chrome" on the streamlined raised panel,
with "Forged in U.S.A." on the back side.
The overall length is 4.1 inches,
and the finish is chrome plating.
The plated finish and lack of an alloy specification indicate production in the post-war era.
Duro-Chrome "Handy-Hex" 2062 1/2x9/16 Short Box-End Wrench
Fig. 374 shows
a Duro-Chrome 2062 1/2x9/16 box wrench,
stamped "Duro-Chrome" and "Handy-Hex" on the streamlined raised panel,
with the fractional sizes and "Chrome Vanadium Steel" on the back side panel.
The overall length is 4.6 inches.
The finish is plain steel,
possibly with traces of a plated finish.
Specialty Tools
Duro/Indestro also offered a number of specialty tools for various service applications.
Handy-Hex 273 11/16x11/16 Head and Manifold Wrench
Fig. 375 shows
a Handy-Hex 273 11/16x11/16 Ell-shaped socket and box-end wrench,
stamped "Handy-Hex" and "Made in U.S.A." on the shank,
with "Chrome Vanadium Steel" on the back side.
The overall length is 14.2 inches,
and the finish is nickel plating,
with extensive losses due to wear and rust.
The socket end also has a very faint "Chromium Vanadium" marking (not shown),
possibly indicating that this wrench was made as contract production.
The 1935 Duro catalog lists this wrench for head bolts and manifold nuts
on Ford Models "A", "AA", "B", "BB", "V8-18", and "V8-40".
Duro-Chrome 268 "Handy-Hex" 7/16x1/2 8-Point Brake Wrench
Fig. 376 shows
a Duro-Chrome 268 7/16x1/2 8-point brake wrench,
stamped "Duro-Chrome" and "Chrome Vanadium Steel" with the model number on the shank,
with "Ford Brakes" and "Handy-Hex" and the fractional sizes on the back side.
The overall length is 11.0 inches.
The Duro-Chrome marking and "Chrome Vanadium Steel" specification suggest
production from 1937 to the early 1940s.
Duro-Chrome 2071 "Handy-Hex" 11/16x25/32 S-Shaped Box-End Wrench
The next two figures show examples of an unusual S-Shaped box-end wrench type,
or "double crescent" wrenches as the Duro catalogs called them.
Fig. 377 shows
a Duro-Chrome 2071 11/16x25/32 S-shaped box-end wrench,
stamped "Duro-Chrome" and "Handy-Hex" with the model number on the shank,
with "Chrome Vanadium Steel" on the back side.
The overall length is 8.7 inches.
This wrench bears the modern catalog number 2071,
but retains the "Handy-Hex" marking to show continuity with the older brand.
The Duro-Chrome marking and "Chrome Vanadium Steel" specification suggest
production from 1937 to the early 1940s.
Handy-Hex 02072 3/4x7/8 S-Shaped Box-End Wrench
Fig. 378 shows
an earlier Handy-Hex model 02072 3/4x7/8 S-shaped box-end wrench,
stamped "Handy-Hex and "Made in U.S.A." with the model number on the shank,
with "Chrome Vanadium Steel" on the back side.
The overall length is 9.7 inches.
The Handy-Hex brand with the leading "0" in the model number indicates that this is an early Duro box wrench,
made from the early 1930s to 1936.
Handy-Hex 02081 9/16x5/8 Half-Moon Box-End Wrench
The next figures show two generations of the 02081/2081 half-moon wrench.
Fig. 379 shows
an early Handy-Hex 02081 9/16x5/8 half-moon box wrench,
stamped with "Chrome Vanadium Steel" and "Handy-Hex" on one side,
with "Manifold & Starter" and "Made in U.S.A." on the back side.
The overall length is 7.2 inches,
and the finish is nickel plating,
with some losses due to wear.
The Duro catalogs refer to this style as an "elbow wrench".
An example of the Duro-Chrome version of this model can be seen as the
Duro-Chrome 2081 Half-Moon Box Wrench.
Duro-Chrome (X-Circle) 2081 9/16x5/8 Half-Moon Box Wrench
Fig. 380 shows
a later Duro-Chrome (X-Circle) 2081 9/16x5/8 half-moon box wrench,
stamped "Manifold & Starter" with the
X-Circle logo
and fractional sizes on one side,
with "Duro-Chrome" and the model number plus "Forged in U.S.A." on the back side.
The overall length is 7.1 inches,
and the finish is plain steel.
The lack of an alloy marking and use of the X-Circle logo suggest production
in the later 1943-1945 wartime years.
Duro-Chrome 276AB Piston Pin Tool
Fig. 381 shows
a Duro-Chrome 276AB piston pin tool,
designed to remove and install the piston pins in Ford "A" and "B" models.
The tool is marked "U.S.A." with the model and Duro-Chrome trademark,
as shown in the insets.
The overall length is 9.7 inches,
and the finish is polished steel.
Similar tools were offered by other companies,
for example the
Plomb 6505 Piston Tool.
DuroLite 16S6 Screwdriver
In the 1930s Duro introduced the DuroLite brand for a line of screwdrivers,
and the next figure shows an example.
Fig. 382 shows
a DuroLite 16S6 screwdriver,
marked with the DuroLite brand molded into the plastic handle,
and with "Chrome Vanadium Steel" stamped on the shank.
The overall length is 11.1 inches,
and the finish is plain steel.
Duro-Chrome No. 2100 10 Inch Waterpump Pliers
Fig. 383 shows
a pair of Duro-Chrome No. 2100 10 inch waterpump pliers,
stamped with the X-Circle logo
and "Forged in U.S.A." on the handle.
The overall length is 10.1 inches fully extended.
The finish is plain steel,
indicating a likely manufacturing date of 1942-1945.
The handles of the pliers incorporate bold raised panels with the "streamlined" motif at one end.
Duro-Chrome No. 2114 Battery Pliers with Box-End Handles
The next figure shows a pair of battery pliers with unusual box-end wrench handles,
marked with a design patent.
Fig. 384 shows
a pair of Duro-Chrome 2114 battery pliers,
marked "Forged in U.S.A." with "Des. 119,441" for the design patent.
The design patent #D119,441 was
issued on Mar. 12, 1940 to W.A. Sandy and assigned to Duro Metal Products.
Duro-Chrome No. 2115 Battery Pliers
By 1935 Duro was offering several models of pliers forged from chrome-vanadium steel.
The scan in Fig. 385 from page 18 of the 1935 Duro catalog shows the No. 2115 battery pliers.
Note that the design at that time already included the dart-like motif extending into the handle.
Fig. 386 shows
a pair of Duro-Chrome No. 2115 battery pliers,
marked "Forged in U.S.A." near the pivot.
Note that the handle incorporates a raised panel with one end of Duro's "streamlined" motif.
The overall length is 8.0 inches,
and the finish is cadmium plating.
The cadmium finish indicates a likely manufacturing date of 1942-1945.
The Indestro equivalent of this model can be seen as the
Indestro 3415 Battery Pliers.
Pliers of this type were popular for servicing battery cables,
as the clamp bolt nuts were frequently too rounded by corrosion to be gripped by a wrench.
Battery pliers were produced by several other companies as well,
and examples include the
Herbrand 179 Pliers
and
Utica 524 Pliers.
Duro-Chrome No. 2120 "Steeldraulic" Pliers
In the late 1920s and early 1930s several makes of automobiles (e.g. Hupmobile, Auburn)
were equipped with Steeldraulic brakes,
a brand of mechanical brakes with an odd adjusting mechanism.
Special pliers were required for making adjustments to these brakes,
and not surprisingly the pliers came to be known as Steeldraulic pliers.
Fig. 387 shows
a pair of Duro-Chrome No. 2120 specialty pliers for Steeldraulic brake adjustments,
stamped "Duro Chrome U.S.A." on a raised panel.
The overall length is 5.6 inches,
and the finish is chrome plating with polished faces.
Steeldraulic pliers were produced by several other companies as well,
and examples include the
Blackhawk 2581 Pliers,
Bonney 2581 Pliers,
Herbrand 272 Pliers,
Utica 516 Pliers,
and
Vacuum Grip No. 14 Pliers.
Duro-Chrome No. 2126 Brake Spring Pliers
The scan in Fig. 388 shows
a listing for Duro-Chrome brake spring pliers
from page 18 of the 1935 Duro catalog.
Two models were available, No. 2125 at 5.5 inches and No. 2126 at 13.5 inches.
Note that these pliers already incorporate a dart-like raised panel that would later
become Indestro's "Streamlined" trademark.
Fig. 389 shows
a pair of Duro-Chrome No. 2126 brake spring pliers,
stamped "Duro Chrome U.S.A." on the upper arm.
The overall length is 13.3 inches,
and the finish is nickel plating.
Duro-Chrome 648 Battery Tool
Fig. 390 shows
a Duro-Chrome 648 battery cable lifter,
a tool designed to remove and service battery cable clamps.
The handle is forged with streamlined raised panels,
stamped "648 Duro-Chrome" on one side and "Forged in U.S.A." on the other.
The end is equipped with a 9/16 12-point opening.
The overall length is 7.2 inches,
and the finish is chrome plating with polished faces.
The tool is also marked with a notice for patent
#2,363,350,
issued to W.P. Nail in 1944.
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