Alloy Artifacts  

Starrett, L.S. Company

Table of Contents

Introduction

The L.S. Starrett Company is an important maker of machinist's tools and precision measuring instruments, continuing in operation from its founding in 1880 to the present day.


Company History

The L.S. Starrett Company was founded by the eponymous Laroy S. Starrett in 1880 in Athol, Massachusetts.

[1894 Ad for Starrett Tools]
Fig. 1. 1894 Ad for Starrett Tools. [External Link]

Fig. 1 shows an ad for Starrett tools, as published on page 210 of the January, 1894 edition of Hardware Dealer.


Patents

L.S. Starrett Company: Issued Patents
Patent No.InventorFiledIssuedNotes and Examples

Trademarks

L.S. Starrett Company: Registered Trademarks
Text Mark or Logo Reg. No. First Use Date Filed Date Issued Notes

Tool Identification

Starrett tools are generally easy to identify, with clear markings for the company name.

Starrett sockets are marked only with an "S" in a circle, as shown in the figure below.


S-Circle-2 Logo

[S-Circle-2 Logo]
Fig. 1B. S-Circle-2 Logo.

Fig. 1B shows the S-Circle-2 logo marked on a Starrett pressed-steel socket.

This logo is very similar to the trademarked S-Circle logo used by the H.D. Smith Company, but the Starrett logo will be found only on pressed-steel sockets.


References and Resources

Photographs and observations of particular tools are based on items in the Alloy Artifacts Collection.


Catalog Resources

Starrett has published many catalogs during its long years of operations. Although the earlier catalogs were often printed without a publication date, the effective date of publication can be estimated using printed advertisements for the various catalog editions. Starrett was a frequent advertiser in magazines and trade journals such as Popular Mechanics, Popular Science, and the Machinists Monthly Journal.

Some of the catalog editions noted in advertisements include No. 18 in 1910, No. 19 in 1912, No. 20 in 1913, No. 21 in 1917, No. 22 in 1921, No. 23 in 1926, No. 24 in 1928, and No. 25 in 1930.

L.S. Starrett: Catalog Resources
Catalog Year Notes
    No. 15 (1900?):
No. 15 1900? No copyright, undated. 116 pages.
Available for Download [External Link] from ITCL.
    No. 17 (1902?):
No. 17 1902? No copyright, undated. Includes supplement. 194 pages.
Available for Download [External Link] from ITCL.
    No. 25 (1930):
No. 25 1930 Copyright 1930. 383 pages.
50th Anniversary Edition.
Available for Download [External Link] from ITCL.

Industrial Distributors

Tools from L.S. Starrett were widely available through industrial distributors. We'll add references as time permits.


Selected Tools


Starrett No. 1-7 Compound Action Cutting Pliers

[Starrett No. 1-7 Compound Action Cutting Pliers]
Fig. 2. Starrett No. 1-7 Compound Action Cutting Pliers, with Insets for Side View and Jaw Detail.

Fig. 2 shows a pair of Starrett No. 1-7 compound action cutting pliers, stamped "The L.S. Starrett Co." and "Athol, Mass. U.S.A." on the upper arm, with the model number on one handle. The cutter inserts are marked "For Music Wire", as seen in the lower inset.

The overall length is 7.0 inches. The finish is polished steel, possibly with a thin nickel plating.


Socket Sets

Starrett was also a producer of socket sets intended for automotive service or general maintenance. Only a single standard model was available, the No. 443-A socket set, which included a ratchet, an extension, a universal, a selection of sockets, and a "packer drill" attachment. (The set could also be ordered as the No. 443-B variation without the drill attachment.)

The Starrett socket sets used pressed-steel sockets, making them similar in appearance to the familiar Mossberg or Walden sockets. However, Starrett used a non-standard design with a narrow 5/8 square base for the sockets, making them incompatible with the sockets produced by Mossberg and the rest of the industry. As a result of the narrow base, Starrett sockets could not be driven from the inside with a standard 1/2 square drive stud.

The Starrett No. 443 socket sets were probably first produced around 1911, the date of the patent filing for the ratchet supplied with the sets. Our earliest catalog reference for the set is from Starrett catalog No. 20, published around 1913.

We have several examples of the L.S. Starrett socket sets and are currently preparing them for display.


Starrett No. 443-A Pressed-Steel Socket Set Ratchet

[Starrett No. 443-A Pressed-Steel Socket Set]
Fig. 3. Starrett No. 443-A Pressed-Steel Socket Set, ca. 1913-1915.

Fig. 3 shows an early Starrett No. 443-A socket set in sturdy wooden box. The drive tools consist of a No. 443 ratchet, an extension, a universal, and a drilling attachment, plus a few miscellaneous items. The generous collection of sockets includes 27 standard hex sockets, two square sockets, and one spark-plug (deep) socket.

The standard hex sockets include the 23 sizes from 5/16 to 1 inch by 32nds, plus the four larger sizes 1-1/32, 1-3/32, 1-5/32, and 1-9/32. The sockets are all marked with the fractional size and the Starrett S-Circle logo. The set as shown is missing the 11/16 and 11/32 sockets.

The square sockets in the set have sizes 13/32 and 21/32, of which one (the 21/32) is missing in this example. The spark-plug socket (near the center of the set) has size 29/32.

When considering the sizes in the socket set, keep in mind that Starrett pressed-steel socket sizes were specified as 1/32 oversize, as was the case with Mossberg and other brands of pressed-steel sockets. A discussion of this confusing convention can be found in the section on Size Conventions in our article on the Frank Mossberg Company.

[Detail for Starrett No. 443-A Socket Set]
Fig. 4. Detail for Starrett No. 443-A Socket Set, ca. 1913-1915.

Fig. 4 shows a more detailed view of the lower compartment of the socket set.

The top two rows hold the majority of the hex sockets, followed by a row with the remaining three hex sockets at the left, a 29/32 spark-plug (deep) socket in the center, and a universal joint at the right.

The next row down has pegs for two square sockets (one is missing) at the left, with a circular knob in the center and the packer drill attachment at the right.

The circular knob is referred to as a "thrust plug" in later catalogs, but is not listed in Starrett catalog No. 20. The thrust plug could be inserted in the drive end of a socket or extension to provide a smooth surface for exerting palm pressure.

The tools at the bottom of the photograph are the No. 443 ratchet and a 6 inch extension. The ratchet in the set is marked "Pat. Applied For", a reference to patent 1,167,948, filed in 1911 by L.S. Starrett et al and issued in 1916.

Since later ratchets are known to have been marked with the patent date, the pending status for this ratchet suggests that this is an early set, probably made between 1913 and 1915. Earlier sets made from 1911 to 1913 probably did not include the thrust plug piece, based on its omission from catalog No. 20.

[Top Cover of Starrett No. 443-A Socket Set]
Fig. 5. Top Cover of Starrett No. 443-A Socket Set, ca. 1913-1915.

Fig. 5 shows the top cover of the early Starrett No. 443-A socket set, marked with a decorative "Starrett Tools" decal in the center.

The dimensions of the box are 14.0 inches wide by 8.1 inches deep by 3.5 inches high.


Starrett No. 443 5/8-Drive Ratchets

The next two figures show examples of the Starrett No. 443 ratchet, beginning with the ratchet from the early set.

[Starrett No. 443 5/8-Drive Ratchet]
Fig. 6. Starrett No. 443 5/8-Drive Ratchet, with Insets for Side View and Marking Detail, ca. 1911-1915.

Fig. 6 shows the Starrett No. 443 ratchet from the early No. 443-A socket set, stamped "The L.S. Starrett Co." and "Athol, Mass. U.S.A." on the head, with "Pat. Applied For" below.

The overall length is 11.0 inches, and the finish is polished steel.

The pending status refers to patent 1,167,948, filed by L.S. Starrett et al in 1911 and issued in 1916.

[Starrett No. 443 5/8-Drive Ratchet]
Fig. 7. Starrett No. 443 5/8-Drive Ratchet, with Insets for Side View and Marking Detail, ca. 1916-1920.

Fig. 7 shows a later Starrett No. 443 ratchet from a No. 443-B socket set. The head is stamped "The L.S. Starrett Co." and "Athol, Mass. U.S.A." with a "Patented Jan. 11, 1916" patent notice.

The overall length is 11.0 inches, and the finish is polished steel.

The patent date refers to patent 1,167,948, filed in 1911 by L.S. Starrett et al.


Starrett 6 Inch Extension from No. 443-A Set

[Starrett 6 Inch Extension]
Fig. 8. Starrett 6 Inch Extension from No. 443-A Set, with Inset for Construction Detail, ca. 1913-1915.

Fig. 8 shows the unmarked 6 inch extension from the early Starrett No. 443-A socket set.

The overall length is 6.3 inches, and the finish is plain steel.


Starrett Pressed-Steel Sockets from No. 443-A Set

[Starrett Pressed-Steel Sockets]
Fig. 9. Starrett Pressed-Steel Sockets from No. 443-A Set, with Inset for Construction Detail, ca. 1913-1915.

Fig. 9 shows a group of three hex sockets from the early Starrett No. 443-A socket set, each stamped on the base with the fractional size and S-Circle logo.

The socket sizes are, from the left, 3/4, 25/32, and 13/16. The finish is plain steel.


Starrett Screwdriver Bit from No. 443-A Set

[Starrett Screwdriver Bit from No. 443-A Set]
Fig. 10. Starrett Screwdriver Bit from No. 443-A Set, with Inset for Side View, ca. 1915-1916.

Fig. 10 shows the unmarked screwdriver bit from the early Starrett No. 443-A socket set, consisting of a square shank with a spring clip riveted in the center. The shank of the bit is approximately 13/32 square, the size required to fit in the drive end of a socket, i.e. with the socket used as a bushing.

The overall length is 3.5 inches, and the finish is plain steel.

Storage for the screwdriver bit was provided by a wooden bracket on the inside of the lid, as seen in the Starrett No. 443-A Set photograph above.


Starrett Thrust Plug from No. 443-A Set

[Starrett Thrust Plug from No. 443-A Set]
Fig. 11. Starrett Thrust Plug from No. 443-A Set, with Insets for Side and Top Views, ca. 1915-1916.

Fig. 11 shows the unmarked thrust plug from the early Starrett No. 443-A socket set, designed to fit into the drive end of the Starrett sockets. The shank is flattened on one side with a spring clip on the opposite side.

The overall height is 1.0 inches, and the diameter of the top is 0.96 inches. The finish is plain steel.


Starrett 5/8-Drive Drill Attachment from No. 443-A Set

[Starrett 5/8-Drive Drill Attachment]
Fig. 12. Starrett 5/8-Drive Drill Attachment from No. 443-A Set.

Fig. 12 shows the unmarked drill attachment shown with the early Starrett No. 443-A socket set. The drill attachment consists of a 5/8-drive adapter threaded to screw into the knurled body, and the drive end of the adapter has a tapered square opening (not shown) for holding the drive stud of an older-style drill bit.

The overall length is 5.1 inches in the retracted position. The finish is plain steel.


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