Top Kōgyō

Table of Contents

Introduction

Top Kōgyō is a tool company operating in Niigata prefecture with roots going back to 1939 as the Hokuetsu Machine Works Company.

Company History

The company was established in 1939 as the Hokuetsu Machine Works Company, with an initial location at 1-525 Oaza-Sanjo, Sanjō City, Niigata Prefecture, Japan. By 1943 the company was making forgings for aircraft parts for the Nakajima Aircraft Company.

Name Change and New Factory

In 1944 the company changed its name to the Nakajima Precision Forging Company (中島精密鍛造 or "Nakajima Seimitsu Tanzō"), and by November of 1945 the company was manufacturing forged tools in a factory located at 2624 Tajima in Sanjō City.

The "TOP" Brand

In 1949 the company adopted "TOP" as a brand for adjustable (monkey) wrenches.

In July of 1950 the company began an association with tool dealers from Tokyo, Osaka, and Nagoya. This association likely included Meisei Tsushō, an export marketing and distribution company which established the Daido Corporation U.S.A. in 1951. (See our notes on Meisei Tsushō for additional information.)

First JIS Certification

On June 28, 1951 Nakajima Precision Forging received JIS certificate 656 for adjustable wrenches (class B4604). The record for this certification can be seen in the 1952-01 Monthly Report for Classes B4604 and B4605. [Editor's note: this is not mentioned in the company's history, but should be.]

On November 16, 1953 the company received JIS certificate 2717 for class B4614 (combination pliers). The record for this certification can be seen in the 1955 JIS Summary for Class B4614.

Production for Meisei Tsushō

During the 1950s Nakajima Precision Forging became an early production partner of Meisei Tsushō and began producing adjustable wrenches for the Truecraft Tool Company of Chicago, which were probably distributed through the Daido Corporation U.S.A. [Editor's note: this is not mentioned in the company's history.]

In 1961 the company built a forging factory to increase production. [Editor's note: where was the factory?]

Name Change to Top Kōgyō

In September of 1963 the company changed its name to the Top Kōgyō Company.

On September 15, 1964 the company received JIS certificate 364148 for class B4630 (open-end wrenches). The record for this certification can be seen in the Aggregated Monthly Reports for 1964-12.

On December 2, 1965 the company received JIS certificate 365198 for class B4631 (needlenose pliers), JIS 365199 for class B4635 (diagonal cutters), and JIS 365200 for class B4632 (box-end wrenches). The records for these certifications can be seen in the Aggregated Monthly Reports for 1966-02, Aggregated Monthly Reports for 1966-02, and Aggregated Monthly Reports for 1966-02.

Contract Production

During the 1960s and 1970s Top Kōgyō was a major production partner for the Truecraft brand of the Daido Corporation. The company supplied adjustable wrenches and several kinds of pliers, and possible other kinds of tools as well.

Top Kōgyō is also known to have supplied tools for the Westline brand of Western Auto Supply, in particular adjustable wrenches and pliers.

Top Kōgyō supplied JIS-certified adjustable wrenches to a number of Japanese companies, including Tone and Matsusaka Iron Works (MCC). These wrenches were typically marked with the company's JIS 656 certification number and a "TK" ID mark.

New Factory at Tsukanome

In August of 1981 the company moved its forge and die operations to the Tsukanome Kinzoku Kōgyō Industrial Park in Sanjo City, and by July of 1982 had fully relocated the forging operations to Tsukanome. In 1983 and 1984 the company transferred a number of its JIS certifications to the Tsukanome factory, which can be seen in the Aggregate Monthly Reports for Top Kōgyō (トップ工業).

By 1987 Tsukanome had become the company's main factory.

In 1987 the company signed a contract with Klein Tools for production of adjustable wrenches.

JIS Consolidation

On March 27, 1991 (Heisei 3.3.27) some of the company's JIS certificates were canceled in what appears to be an administrative change, in order to group separate certifications into a single JIS number. The November 1991 Monthly Report listed the canceled JIS numbers as 365198 (class B4631) and 365199 (class B4635). These cancelations can be seen in the Aggregate Monthly Reports for Top Kōgyō (トップ工業).

However, if we look ahead to the 1999 Summary, Top Kōgyō is listed with certificate 365198 for classes B4623, B4625, B4631, and B4635. Why would 365198 be canceled if it was to be used later for all of the pliers?

Our interpretation is that the 1991 report was erroneous, and that instead of 365198 being canceled, the actual canceled certificate was 383105 (classes B4623 and B4625). This would leave 365198 as the remaining active certificate for the four classes of pliers, as reported in the 1999 Summary. We have corrected this error in the JIS database.

JIS Certification for B4651

On January 11, 2002 the company received JIS certification for combination wrenches (class B4651), but the certification number isn't known yet.

Continuing Operations

The company's website (in Japanese) is at Top Kōgyō Company [External Link]. Our history was adapted from the company's historical timeline.

Patents

Trademarks

Top registered a number of Japanese trademarks plus at least one US trademark, for "TOP" in stylized text.

JIS Certification History

TOP Kōgyō is known to have received JIS certifications in classes B4604 (adjustable wrenches), B4614 (combination pliers), B4623 (side-cutting pliers), B4630 (open-end wrenches), B4631 (needlenose pliers), and B4651 (combination wrenches).

Factory locations were at 2624 Tajima in Sanjo City and 2190-5 Tsukanome, both in Niigata prefecture.

The company is known to have provided JIS-certified contract production using its JIS 656 certification and a "TK" code as the ID mark.

View Company History with Factories for TOP Kōgyō.

View JIS Certification Events for TOP Kōgyō.

Background information on the JIS program can be found in the section on the Japanese Industrial Standards.

Tool Identification

Tools made by Top Kōgyō were typically marked with the "Top" trademark.

Some open-end wrenches were marked with "Liner Top".

The company used "TK" as its JIS ID code, and some contract production may be marked with this code.

References and Resources

Additional information can be found on the company's website (in Japanese) at Top Kōgyō Company [External Link].

The website includes a current catalog illustrating their products.

Adjustable Wrenches

Top H-200 200mm Adjustable Wrench

Fig. 1. Top H-200 200mm Adjustable Wrench, with Insets for Back Side, Side View, Construction Detail, and Marking Detail, 1992.

Fig. 1 shows a Top H-200 200mm adjustable wrench, marked with "Top" and "Heavy Duty" plus the JIS-Circle logo and "H 656" forged into the front, with "Chrome Vanadium" plus "Japan" and "92JI" forged into the back.

The lower inset shows a close-up of the jaws to illustrate the construction details. Note the angled transition at the fixed jaw and the corresponding angled cutaway on the movable jaw.

The overall length is 8.1 inches and the maximum opening is 1.0 inches. The head thickness was measured at 0.50 inches.

The finish is chrome plating with highly polished faces.

The "656" marking refers to JIS certificate 656, first received by the company in 1951.

The "92JI" marking is believed to be a year/month date code for September of 1992. (We're not sure what the trailing "I" means in this case.)

Open-End Wrenches

Top 10x12mm Open-End Wrench

Fig. 2. Top 10x12mm Open-End Wrench, with Inset for Back Side.

Fig. 2 shows a Top 10x12mm open-end wrench with depressed oval panels, marked with the "Top" oval logo and the JIS-Circle+S logo forged into the front panel, with a code (possibly "8-AI") forged into the back panel.

The shank is also marked with the metric sizes forged into the front.

The overall length is 5.2 inches, and the finish is chrome plating with a matte surface.

The absence of a "Japan" marking on this tool indicates that it was originally produced for the Japanese domestic market.

Top 12x14mm Open-End Wrench

Fig. 3. Top 12x14mm Open-End Wrench, with Inset for Back Side.

Fig. 3 shows a Top 12x14mm open-end wrench with depressed oval panels, marked with "Top" and the JIS-Circle+S logo forged into the front panel, with "Chrome Vanadium" forged into the back panel.

The shank is also marked with the metric sizes forged into the front.

The overall length is 5.7 inches, and the finish is chrome plating with polished faces.

The absence of a "Japan" marking on this tool indicates that it was originally produced for the Japanese domestic market.

Liner Top 17x19mm Open-End Wrench

Top Kōgyō offers a series of "Liner Spanners", but we're uncertain of their defining characteristics other than being open-end wrenches. The next two figures show examples of Liner wrenches.

Fig. 4. Liner Top 17x19mm Open-End Wrench, with Inset for Back Side.

Fig. 4 shows a Liner Top 17x19mm open-end wrench with depressed oval panels, marked with "Liner Top" forged into the front panel, with a "7-JI" code and the JIS-Circle+S logo forged into the back panel.

The shank is also marked with the metric sizes forged into the front.

The overall length is 7.3 inches, and the finish is chrome plating with a matte surface.

The absence of a "Japan" marking on this tool indicates that it was originally produced for the Japanese domestic market.

Liner Top 21x23mm Open-End Wrench

Fig. 5. Liner Top 21x23mm Open-End Wrench, with Inset for Back Side.

Fig. 5 shows a Liner Top 21x23mm open-end wrench with depressed oval panels, marked with "Liner Top" forged into the front panel, with a "7-HI" code and the JIS-Circle+S logo forged into the back panel.

The shank is also marked with the metric sizes forged into the front.

The overall length is 8.9 inches, and the finish is chrome plating with a matte surface.

The absence of a "Japan" marking on this tool indicates that it was originally produced for the Japanese domestic market.

Box-End Wrenches

Top 36x41mm Specialty Box-End Wrench

Fig. 6. Top 36x41mm Specialty Box-End Wrench, with Inset for Back Side.

Fig. 6 shows a Top 36x41mm specialty box-end wrench with laterally offset openings, somewhat similar to an S-shaped wrench.

The wrench is marked with "Top" and the metric sizes forged into the front, with "Chrome Vanadium" and the sizes forged into the back side.

The overall length is 18.3 inches, and the finish is chrome plating.

The absence of a "Japan" marking on this tool indicates that it was originally produced for the Japanese domestic market.

Pliers

Top RA-0150 150mm Needlenose Pliers with Side-Cutters

Fig. 7. Top RA-0150 150mm Needlenose Pliers, with Insets for Back Side, Side View, and Marking Detail.

Fig. 7 shows a pair of Top RA-0150 150mm needlenose pliers with side-cutters, stamped with the "Top" oval logo and model number across the pivot, with the JIS-Circle logo below.

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

The JIS symbol is a reference to JIS certificate 365198, first received by the company in 1965.

Top HP-250 250mm Tongue-and-Groove Waterpump Pliers

Fig. 8. Top HP-250 250mm Tongue-and-Groove Waterpump Pliers, with Insets for Side View and Marking Detail, 1993.

Fig. 8 shows a pair of Top HP-250 250mm tongue-and-groove waterpump pliers, stamped with "Top" and the model number on the upper handle, with "Cr-V" and "JAPAN 93H" forged into the bottom handle.

The overall length is 10.0 inches closed and 10.5 inches fully extended, and the finish is chrome plating.

The "93H" marking is believed to be a year/month date code indicating production in August of 1993.

The handles of the pliers have a rough finish and show the parting line from the forging step, indicating that they were originally covered with plastic hand grips. (We're planning to replace the grips with heat-shrink tubing.)

These pliers incorporate some advanced design and construction features based on prior patents for tongue-and-groove pliers.

First note the shelf of metal at the inside edge of the grooves on the lower handle. This was the key feature in the second-generation Channellock patent 2,592,927, filed by H.H. Manning in 1949 and issued in 1952. Adding the metal shelf relieves the stress that would otherwise be concentrated at the gaps between the deep grooves.

An example of pliers with this feature can be seen in the Later Channellock 426 Pliers.

A second notable feature is that the grooves have been undercut, as can be seen in the top inset. Undercut grooves are desirable in order to lock the two handles together when gripping an object, without placing any stress on the connecting bolt. And although it's not readily visible in the photos, the grooves were actually formed by precision forging rather than by machining.

Normally it's an axiom of drop-forging that forging dies cannot have undercut edges, as this would cause the workpiece and die to become locked together. But in the early 1970s J.E. Swanstrom Jr. of Diamond Tool developed a way to directly forge undercut grooves on pliers, which is described in patent 3,739,664, filed in 1971 and issued in 1973.

An example of pliers with forged undercut grooves can be seen in the Diamalloy HL18P "Groove-Joint" Pliers.

These are the first pliers we've seen that incorporate the design and construction features from both the 1952 Manning patent 2,592,927 and the 1973 Swanstrom patent 3,739,664. The latter patent expired in 1990, and presumably soon afterwards the engineers at Top Kōgyō would have redesigned their forging dies with undercut grooves.

Contract Production for Matsusaka Iron Works (MCC)

In its early years MCC produced its own partially-forged adjustable wrenches, but in later years the company turned to Top Kōgyō for contract production of fully-forged wrenches.

[Top] MCC "TK" 200mm Adjustable Wrench

Fig. 9. MCC "TK" 200mm Adjustable Wrench, with Insets for Back Side, Side View, Construction Detail, and Marking Detail, 1992.

Fig. 9 shows an MCC 200mm adjustable wrench, marked with "MCC" and "Heavy Duty" plus the JIS-Circle+H logo forged into the front, with "CR-VA" and "Drop Forged Steel" plus "Japan" forged into the back.

The wrench is also marked with "656" and "TK" forged into the front, with a "92CI" code forged into the back, as seen in the upper composite inset.

The lower inset shows a close-up of the open jaws, illustrating the angled transition at the corner of the fixed jaw and the angled cutaway of the movable jaw.

The overall length is 8.2 inches and the maximum opening is 1.0 inches.

We were not able to remove the pin securing the worm gear, but the walls of the bore are threaded, indicating that the pin is threaded on the outside end.

The "656" marking indicates production by Top Kōgyō, which received JIS certificate 656 for class B4604 in 1951. The "TK" marking is the company's JIS ID mark.

The "92CI" code is believed to be a year/month date code for March of 1992. (We're not sure what the trailing "I" means in this case.)

Contract Production for Tone Company

Top Kōgyō was a supplier of open-end wrenches to the Tone Company.

[Top] Tone Tool [LS-2123] "TK" 21x23mm Long Open-End Wrench

Fig. 10. Tone Tool [LS-2123] "TK" 21x23mm Long Open-End Wrench, with Inset for Back Side.

Fig. 10 shows a Tone Tool [LS-2123] 21x23mm long open-end wrench with oval recessed panels, marked with "Tone-Tool" and "Japan" forged into the front panel, with "Cr-V Steel" and "T.K" forged into the back panel.

The wrench is also marked with the metric sizes forged into recessed panels on both sides.

The overall length is 9.6 inches, and the finish is polished chrome plating.

This wrench is part of the Tone long-format LS-series, which do not meet JIS specifications for class B4630 due to the extra length.

The "T.K" marking identifies the maker as Top Kōgyō, which used "TK" as its JIS ID mark. (Note though that the usage here is technically not a JIS ID mark, since the wrench is not JIS-certified.)

Contract Production for Truecraft

Top Kōgyō was a major supplier to the Truecraft brand managed by the Daido Corporation, and even supplied tools to the American Truecraft Tool Company before the Truecraft trademark was acquired by Daido.

Tools supplied by Top included adjustable wrenches, open-end and combination wrenches, and various types of pliers.

[Top] Truecraft Tool 6 Inch Adjustable Wrench

Fig. 11. [Top] Truecraft Tool 6 Inch Adjustable Wrench, with Inset for Back Side, ca. 1950s.

Fig. 11 shows shows a Truecraft Tool 6 inch adjustable wrench, marked with "Truecraft Tool Company" and "Japan" forged into the front, with "Drop Forged Alloy Steel" and "TOP" forged into the back.

The wrench is also marked with "N" and a "6 - 1" production code forged into the back.

The overall length is 6.0 inches, and the finish is plain steel.

The "TOP" marking indicates production by Top Kōgyō, which during the 1950s was still known as the Nakajima Precision Forging Company.

This wrench is a rare example of a tool made for the (American) Truecraft Tool Company prior to the acquisition of the "Truecraft" trademark by the Daido Corporation.

[Top] Truecraft F208 8 Inch Adjustable Wrench

Fig. 12. [Top] Truecraft F208 8 Inch Adjustable Wrench, with Insets for Edge View and Back Side Detail, ca. 1960s to 1975.

Fig. 12 shows a [Top] Truecraft F208 8 inch adjustable wrench, marked with "Drop Forged Tool Steel" and "Top" forged into the shank, with "Truecraft Tool" and "Japan" forged into the back side.

The back side is also stamped with the "F208" model number on a small raised panel.

The overall length is 7.9 inches, and the maximum opening is 0.9 inches. The head thickness was measured at 0.47 inches.

The finish is chrome plating with polished faces.

The leading "F" of the model number indicates production up to around 1975.

The "Top" marking indicates production by the Top Kōgyō Company. The forged-in code "8-84" below the "Top" marking resembles a date, but the meaning is not known.

One construction characteristic to note is that the pin securing the worm gear is threaded on the inside end.

[Top] Truecraft K506 6 Inch Tongue-and-Groove Pliers

Fig. 13. [Top] Truecraft K506 6 Inch Tongue-and-Groove Pliers, with Insets for Side View and Marking Detail, 1971.

Fig. 13 shows a pair of [Top] Truecraft K506 6 inch tongue-and-groove pliers, stamped with "Truecraft" and the model number on the upper handle, with "Forged" and "Top Japan 71A" on the botton handle.

The overall length is 7.1 inches fully extended, and the finish is chrome plating with polished faces.

The leading "K" of the model number indicates production up to around 1975.

The "Top" marking indicates production by the Top Kōgyō Company, and a check of their web site found similar pliers were made in the past, although now discontinued.

The "71A" marking is believed to be a year/month date code indicating production in January of 1971. On its own, the Truecraft K508 model number would suggest production from the late 1960s to mid 1970s.

[Top] Truecraft K406 6 Inch Needlenose Pliers with Side Cutters

Fig. 14. [Top] Truecraft K406 6 Inch Needlenose Pliers, with Insets for Back Side, Side View, and Marking Detail, ca. Mid 1960s to 1975.

Fig. 14 shows a pair of [Top] Truecraft K406 6 inch needlenose pliers with side cutters, stamped with "Truecraft" and the model number around the pivot, with "Japan" and "Top 70J" on the back side.

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

The leading "K" of the model number indicates production up to around 1975.

The "Top" marking indicates production by Top Kōgyō.

Contract Production for Western Auto Supply

In the mid 1950s Top Kōgyō began supplying tools to the Westline brand managed by Western Auto Supply.

Top Kōgyō was a production partner of the Daido Corporation, and the Westline tools were likely imported and distributed by Daido.

Tools made by Top for the Westline brand include adjustable wrenches, combination pliers, and diagonal cutters. We will add examples as they become available.

[Top] Westline H5052 8 Inch Adjustable Wrench

Fig. 15. [Top] Westline H5052 8 Inch Adjustable Wrench, with Insets for Back Side, Side View, and Construction Detail, ca. Mid to Late 1950s.

Fig. 15 shows a Westline H5052 8 inch adjustable wrench, marked with "Westline" and "Japan" forged into the front, with "Drop Forged Tool Steel" and "TOP" forged into the back.

The wrench is also marked with "N" and a "2 - 4" production code forged into the back.

The overall length is 8.0 inches and the maximum opening is 1.0 inches. The finish is nickel plating with polished faces.

The "TOP" marking indicates production by Top Kōgyō.

[Top] Westline H5005 6 Inch Thin Combination Pliers

Fig. 16. [Top] Westline H5005 6 Inch Thin Combination Pliers, with Insets for Back Side, Side View, and Marking Detail, ca. 1960s?

Fig. 16 shows a pair of Westline H5005 6 inch thin combination pliers, stamped with "Westline" and the model number along an oval arc.

The pliers are also marked with with "TOP Drop Forged Japan" forged into the undersides of the handles.

The top inset shows a side view of the pliers, illustrating the thin nose and the diamond-checkered gripping pattern on the handles.

The overall length is 6.1 inches, and the finish is polished chrome plating.

The "TOP" marking indicates production by Top Kōgyō.

We disassembled the pliers for cleaning and observed an "827" code stamped on one handle near the pivot.

These pliers are very similar to the Fuller 191-6 6 Inch Thin Combination Pliers shown in our article on the Fuller Tool Company. In particular, the diamond-checkered gripping pattern on these pliers is very similar to the pattern used by Fuller, and the marking style with the brand name along a curved arc was also used by Fuller.

However, on close examination we found that there are some subtle differences. The diamond pattern on the Westline pliers has equal dimensions in the longitudinal and transverse directions, whereas Fuller's pattern is slighly elongated in the longitudinal direction. In addition, the forgings for the Westline pliers have a shallow depressed panel in the pivot area, but the Fuller pliers have flat surfaces in the pivot area.

We think this is a case of convergent design, with Top Kōgyō being asked to make pliers similar to the Fuller models. As a supplier to hardware stores, Fuller would have been a competitor to Western Auto Supply, so Western Auto would have wanted to offer comparable products.