Kyoto Tool Company (KTC)

Table of Contents

Introduction

The Kyoto Tool Company (in Japanese 京都機械工具 or "Kyoto Kikai Kōgu"), generally known as KTC, is probably the best known and most celebrated Japanese toolmaker. The company offers high quality tools for professional use under the KTC and Nepros brands.

Company History

The Kyoto Tool Company (京都機械工具) was founded in 1950 by Kiichi Saitō (斉藤喜一), Sojiro Yamazaki (山崎宋次郎), and Masayuki Ushiro (宇城正行), all of whom had previously been key employees of the tool division of Kyoto Kikai. The company's initial business contract was with Toyota Motors to supply tools for vehicle tool kits, and the company's early factory was at 38 Hinagajo-cho, Minami-ku in Kyoto City.

The Toyota contract had previously been held by Kyoto Kikai, but followed the founders to their new company.

We were quite interested to learn of the formation of KTC by ex-employees of Kyoto Kikai, rather than as a business succession via spinoff or as a newly independent subsidiary. KTC's own history dwells at some length on the early history of Kyoto Kikai, leaving an impression that KTC is the heir by succession of the earlier company's heritage.

In the U.S. and other Western countries it's fairly common for employees to leave one company and set up a competing business, but in Japan at that time it was probably unusual.

The Karasuma Factory at Higashikujo

In 1951 the company moved to a new factory at 36 Torimaru-cho, Higashikujo, Shimogyō-ku, Kyoto City (京都市下京区東九条鳥丸町 36) and began manufacturing commercial tools. The company referred to this as the Karasuma (鳥丸) factory.

Early JIS Certification

On November 11, 1952 KTC received JIS certification 1977 for class B4630 (open-end wrenches) at the Karasuma factory. The record for this certification can be seen in the section on the Monthly Report 1952-11 for Class B4630.

The Oike Factory at Nakagocho

In 1952 the company built a new factory and moved to Nakagocho, Nakagyo-ku in Kyoto. This factory was referred to as the Oike (御池) factory after a nearby famous area in Kyoto.

On October 21, 1954 the company received JIS certification 3487 for class B4614 (combination pliers) at the Oike factory. The record for this certification can be seen in the section on the 1955 JIS Summary for Class B4614.

On November 22, 1954 the company received JIS certification 3523 for class B4604 (adjustable wrenches) at the Oike factory. The record for this certification can be seen in the section on the 1955 JIS Summary for Class B4604. (This certification was later upgraded to include both normal and strong grades, but we don't know the exact timing.)

On September 6, 1955 the company received JIS certification 4247 for classes B4636 (socket wrenches) and B4637 (extension bars) at the Oike factory. The record for this certification can be seen in the section on the 1958 JIS Summary for Classes B4636, B4637, and B4639.

The 1962 Certified List reports that the JIS 1977 certification for class B4630 had moved to the Oike factory, but we haven't found a record documenting the move.

On August 10, 1959 the company received JIS certification 6853 for classes B4638, B4640, and B4641 at the Oike factory. The record for this certification can be seen in the section on the 1962 JIS Summary for Classes B4638, B4640, and B4641.

[Editor's note: these JIS certifications are not mentioned in the company history.]

Kyoto Kōki Subsidiary

In 1960 KTC acquired Nakagawa Kōki and formed Kyoto Kōki as their first subsidiary. Nakagawa Kōki had been founded by Eiji Nakagawa and made slip-joint pliers as its main product.

Contract Production for Fuller Tool

KTC's published history has an interesting story noting that in 1960 Bernard Fuller of the Fuller Tool Company came to visit the KTC factory, and afterwards took sample wrenches back to the United States. The result was a 1961 export contract between KTC and Fuller Tool, which is known to have included adjustable wrenches, open-end wrenches, and combination wrenches. KTC continued to supply tools to Fuller for many years.

A further anecdote from the 1960 visit is that after returning home, Fuller sent some of the sample wrenches to Sears to be tested, and this set in motion events that would lead to the Sears "BF" line of Japanese import tools.

The Fuller tools supplied by KTC were of very high quality, much better than the "hardware store" grade that might have been expected. The early open-end wrenches were similar to KTC's own JIS-certified wrenches, with a recessed panel design and crisp forged-in markings noting chrome vanadium steel. In addition, the wrenches were marked with the KTC-Oval trademark rather than passing as generic production.

Although the Fuller wrenches would have been expensive to produce due to the need for custom dies, the Fuller production could be regarded as a calculated investment on KTC's part, with each wrench advertising the capabilities of the producer. The 1961 Fuller export contract was important enough that KTC specifically mentions it in the history timeline of their website.

New Factory in Fushimi-ku

In 1964 the company relocated to a new factory at 40 Shimo toba, Nagatamachi, Fushimi-ku, Kyoto, and the new facility became designated as a "model factory".

JIS certificate 3523 was transferred from the Oike factory to Fushimi-ku on December 16, 1964.

Contract Production for Sears Roebuck

By 1964 KTC had begun supplying tools to Sears Roebuck under the "BF" manufacturer's code, initially with "Sears" brand adjustable wrenches and carbon steel drop forged wrenches. The carbon steel wrenches were designed as copies of the Sears "Dunlap" brand wrenches of the late 1950s, and an example can be seen as the [KTC] Sears "BF" 9/16x5/8 Open-End Wrench.

In addition, KTC probably supplied slip-joint pliers through its Kyoto Kōki subsidiary, but we are still gathering evidence for this production.

Pipe Wrench Development

In the mid 1960s the company began an intensive project to develop pipe wrenches for the export market, which is covered in some detail in KTC's published history. The project began with a request from the Fuller Tool Company, and Fuller sent samples of Ridgid-pattern pipe wrenches to KTC for analysis and study.

At that time most heavy-duty pipe wrenches were being made with cast malleable iron bodies, but after analysis KTC decided to use ductile cast iron instead, which had strength similar to steel and would allow reduced weight. KTC was able to find a foundry run by the Shimadzu Corporation which could make the required ductile castings, but because of the greater cost of the material, it required six months of research and development to find the right balance between strength and cost.

The result was a heavy-duty (Ridgid pattern) pipe wrench constructed with a ductile cast iron body, which was well received by the market. KTC reported selling 700,000 units in the U.S. and Australia in the first three years.

KTC's history doesn't provide a timeline for the pipe wrench program, but if we work backwards from the listing for heavy-duty pipe wrenches in the 1968 Craftsman catalog, the wrenches were probably ready for production by late 1966 or early 1967. (Sears would have needed some time for testing and catalog preparation.)

The pipe wrenches were initially offered by KTC and Fuller, and by 1968 KTC was supplying "Sears" brand heavy-duty pipe wrenches. These wrenches have been observed marked with the KTC logo and a "BF" code, an example of which can be seen as the Sears 30852 "BF" 14 Inch Pipe Wrench.

The development project also produced a Stillson-pattern pipe wrench, which was offered by Fuller and by Sears beginning in 1969.

Craftsman Combination Wrenches

By 1969 KTC was supplying "Craftsman" combination wrenches, an important milestone as the first "BF" series tool for the Craftsman brand.

The Hokuriku KTC Tool Company

In 1970 the company established the Hokuriku KTC Tool Company in Hakui City, Ishikawa Prefecture, which provided additional production capacity. The Hokuriku KTC factory was located at 150-1, Yanagida-cho 70, Hakui City.

Hokuriku KTC was a quasi-independent company and received JIS certifications under its own name, but since it provided production for KTC, we are treating it as a factory for KTC.

Pipe Wrench Certification

Sometime between 1967 and 1972 class B4606 (pipe wrenches) was added to KTC's JIS 3523 certification, but without changing the date, so that we don't know the exact date of the pipe wrench certification. The record for this certification can be seen in the 1972 JIS Summary for Classes B4604 and B4606.

New Factory at Kumiyama

In 1979 the company started relocating production to a new factory in Kumiyama-cho, Kuse-gun, Kyoto Prefecture. The factory at Fushimi-ku continued production of certain tools for some years afterwards, but eventually was closed.

JIS 3523 for class B4604 and JIS 4247 for class B4636 were transferred to Kumiyama on June 26, 1979.

JIS certification for Kyoto Kōki

On June 26, 1979 the Kyoto Kōki factory received JIS 579037 for class B4614 (combination pliers). The record for this certification can be seen in the 1982 Summary for Class B4614.

After Kyoto Kōki received JIS certification, KTC transferred production of combination pliers to its subsidiary. Kyoto Kōki used a K-Circle mark as its JIS ID code.

Mirror Tools

In 1984 the company released its line of Mirror tools with a highly polished finish.

In 1985 Hokuriku KTC received JIS certificate 474026 for combination wrenches (class B4651). Documentation for this certification can be found in the 1999 Summary for Super-Class B027.

In 1988 the head office moved to Kumiyama-cho.

In 1988 Hokuriku KTC received JIS certificate 488006 in classes B6404 (adjustable wrenches) and B4606 (pipe wrenches). Documentation for this certification can be found in the 1999 Summary for Super-Class B013.

The Nepros Line

In 1995 the company released the Nepros line of "Mirror" tools.

In 2003 the KTC Manufacturing Technology Museum was opened to the public.

Continuing Operations

KTC continues in operation today at Kumiyama-cho, and the company maintains a website (in Japanese and English) at KTC Kyoto Tool [External Link]. Our history was adapted from the historical timeline on the Japanese site.

Patents

The table below shows some of KTC's early patents that are mentioned in the catalogs.

Trademarks

KTC registered trademarks in both Japan and the United States.

JIS Certification History

KTC received JIS certifications for classes B4604 (adjustable wrenches), B4606 (pipe wrenches), B4614 (combination pliers), B4630 (open-end wrenches), B4632 (box-end wrenches), B4636-B4641 (socket wrenches), B4643 (bolt cutters), and B4651 (combination wrenches).

Factory locations were in Higashikujo (Karasuma), Nakagocho (Oike), Yanadiga-cho, and Kumiyama-cho.

View Company History with Factories for KTC.

View JIS Certification Events for KTC.

Kyoto Kōki received a JIS certification for class B4614 (combination pliers). The factory location was Oyamazaki-chō.

View Company History with Factories for Kyoto Kōki.

View JIS Certification Events for Kyoto Kōki.

Tool Identification

Tools from Kyoto Tool are typically marked with the KTC-Oval symbol consisting of "KTC" inside an oval. This symbol was registered as a US trademark in 1991.

Early tools were generally marked with the KTC-Double-Circle logo, known as nijūmarukyo (二重丸京) in Japanese.

In addition to selling its own brands, the company also provides extensive contract manufacturing services for a number of customers, and KTC-made tools can be found under many other brands.

KTC-Double-Circle Logo

Fig. 1 shows the KTC "Double Circle" logo, known as nijūmarukyo (二重丸京) in Japanese.

This was the early logo used by KTC from 1950 until the early 1960s.

KTC-Oval Logo

Fig. 2 shows the KTC-Oval logo as it was presented for trademark #1,663,191.

Fig. 3 shows the KTC-Oval logo, as stamped on a Fuller 3/4 combination wrench shown in a later figure.

KTC Standard Forged Markings

KTC provided extensive contract production for the Sears "BF" series tools, which included a line of carbon steel drop-forged wrenches with forged-in markings. The next set of figures show the standard marking style on these wrenches, which included several variations. These markings should serve as a reliable means to identify KTC production.

Based on the observed examples, the "standard" markings underwent some evolution, and these changes may assist with estimating the production date for a tool.

Fig. 4 shows the earliest version of the KTC Standard Forged Markings, as observed on a Sears "BF" 13/16x7/8 Open-End Wrench.

In this example the "BF" and "JAPAN" markings have been split by "DROP FORGED", and the panel does not repeat the size markings from the other side. Some further variations include "B.F" at the left.

This first generation of the standard markings has been observed on open-end wrenches and combination wrenches.

Fig. 5 shows the second generation of the KTC Standard Forged Markings, as observed on a Sears "BF" 5/8 Combination Wrench.

In this example "DROP FORGED" is in the center with size markings at both ends of the panel, and the "BF" and "JAPAN" markings have been joined at the right.

This second generation of the standard markings has been observed on open-end, combination, and box-end wrenches.

Fig. 6 shows the third generation of the KTC Standard Forged Markings, as observed on a Sears "BF" 9/16x5/8 Offset Box-End Wrench.

In this example "DROP FORGED" has been replaced by "FORGED" in the center of the panel, with "BF JAPAN" in smaller letters to the right, and size markings at both ends.

This third generation of the standard markings has been observed on open-end, combination, and box-end wrenches.

The examples above show that the markings evolved through three generations, during which the "BF Japan" marking was consolidated after being split apart in earlier versions, and "Drop Forged" changed to "Forged".

We can roughly estimate the date ranges for the generations by noting that the third generation was in use by the mid 1970s. This suggests that the first generation ranged from 1964 to the mid 1960s, the second generation ranged from the mid 1960s to mid 1970s, with the third generation from the mid 1970s onward.

References and Resources

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

Catalog Resources

Selected Tools

Currently most of our examples of KTC's tools are contract production for other brands, including Toyota, Nissan, Fuller, and Sears. These tools are shown in the sections below.

KTC offers an extensive selection of tools under its own brands, and we will add examples as they become available.

Adjustable Wrenches

Adjustable wrenches were an important product for KTC, and we are planning to present several examples to show the development and evolution of these tools. But first we want to discuss some puzzling questions about whether KTC used in-house or contract production for these tools during the mid 1950s to 1980s time frame.

Background History

In 1954 KTC received JIS certificate 3523 for adjustable wrenches at its Oike (Nakagocho) factory, and in late 1964 JIS 3523 was transferred to the new factory at Fushimi-ku.

After receiving certification, most companies would add JIS markings to their adjustable wrench production. In Japan of the mid 1950s and later, JIS certification was generally required for sales to commercial, government, and military customers, and since KTC is a major tool company, we would expect to find numerous examples of KTC adjustable wrenches marked with its JIS certification.

However, the CWC site reports that KTC adjustable wrenches with KTC's own JIS certification are fairly rare, at least until 1988 when the Hokuriku KTC subsidiary received JIS certification for adjustable wrenches.

Prior to the late 1980s we find that adjustable wrenches marked with KTC's brand are frequently marked with another company's JIS certification, indicating contract production for KTC. (Recall that JIS marked tools must be traceable to the actual maker.) The most frequently observed contract maker is Hokuyo Sangyo ("Sanki"), and production by Yamaco has also been seen.

A Mercari Search

To investigate this issue further, we decided to do some research using Mercari, a popular Japanese online marketplace for tools and other products. A recent search (October 2024) for "KTC monkey wrench" turned up many examples of adjustable wrenches.

We restricted our attention to the "classic" style of adjustable wrench of the 1950s to 1980s and ignored the many modern wrenches with cut-away shanks and super-wide openings. The wrenches we examined were all marked for KTC's name and logo, but (as expected) most had forged-in markings indicating production by Sanki. Fortunately we were able to spot some examples with direct relevance to our question.

• An Early Nissan OEM Wrench

  One example that stood out from the rest was marked with the Nissan logo and a JIS symbol, along with KTC's early "nijumarukyo" logo and the company name. The construction of the wrench closely matched the illustration on page 11 [External Link] of the 1966 KTC catalog, which shows some very distinctive production characteristics. Note in particular the rounded inside corner of the fixed jaw, the inset convex cutaway of the moveable jaw, the wide tailpiece of the moveable jaw, and the hanging hole without a ridge.

  A photograph of a similar wrench can be found on the CWC site as the KTC "Nijumarukyo" OEM for Nissan [External Link]. The CWC site actually shows two Nissan OEM wrenches, the first of which was made by Yamaco as contract production for KTC, with the second example made by KTC itself. These wrenches allow us to understand the origin of KTC's style for adjustable wrenches.

  In the early 1950s KTC had a production contract with Nissan, and Nissan apparently requested JIS-certified adjustable wrenches as part of the contract. At that time KTC was not yet certified for adjustable wrenches, so it subcontracted with Yamaco to produce the first generation of the Nissan OEM JIS wrenches, which were marked with Yamaco's "YK" identification mark. (Yamaco had received JIS 2356 on June 20, 1953.)

  Since the tools produced for Nissan were supposed to be marked with KTC's name and logo, Yamaco made the wrenches with markings for KTC, plus the small "YK" code required for JIS traceability. The first wrench displayed by the CWC link above shows an example of Yamaco's production, with a "YK" code visible to the right of the JIS symbol.

  On November 22, 1954 KTC received JIS certificate 3523 for adjustable wrenches, and presumably shortly afterwards began its own production of Nissan OEM wrenches. Since the wrenches made up to this point had been made by Yamaco, KTC copied Yamaco's style for its own wrenches. The second wrench in the CWC link above shows KTC's own production, in the same style as Yamaco but without any additional marks near the JIS symbol.

  We can accept the Nissan OEM wrench as proof that KTC made JIS-certified wrenches in this style.

  Although the Nissan OEM wrench is very similar to the illustration in the 1966 KTC catalog, there is one difference worth noting. The Nissan OEM wrench has jaws with a round or "maru" (丸形) outline, but the 1966 catalog shows the jaws with a "spear type" (ヤリ形) outline. This difference may be helpful in estimating the production date for some adjustable wrenches.

• JIS 9786

  The next significant observation on Mercari was a wrench marked with KTC's name and logo along with a JIS symbol and "9786" forged into the front, with "KTC, FORGED ALLOY" plus a small "SA" marking forged into the back. JIS 9786 was registered to Hokuyo Sangyō, so this wrench was definitely produced by Sanki, and it shows that the "SA" marking indicates Sanki production.

  The wrench construction closely matched the KTC catalog illustration in the jaw details and the absence of a ridge around the hanging hole, which proves that Sanki was able to replicate the "KTC Style" in adjustable wrenches.

• The Remaining Examples

  After examining these first two examples from Mercari, we now know what a KTC JIS-marked wrench looks like, but we also know that looks alone won't distinguish a wrench from a close copy.

  Most of the other listings we examined were very similar to the Sanki example, with a forged-in "SA" on the back and in some cases marked with the full JIS number. However, we did find two listings that appeared to not have the "SA" marking, but were otherwise similar in construction to the other wrenches. (We say "appeared" because the photos were not completely clear.)

  Our hypothesis is that these two wrenches were actual KTC production, and that distinguishing KTC production from contract production must be based on the absence of the seemingly insignificant "SA" mark.

• Conclusions

  From this exercise it is immediately clear that KTC wrenches produced by Sanki represent a substantial majority of the used wrenches available for sale now. To draw further conclusions, we have to start with the assumption that the relative abundance of products in the online marketplace is proportional to their original sales. With this assumption we can make a rough estimate of the proportion of sales by noting that after examining at least ten listings, only two represented possible KTC production. This leads to an estimated 80% market share for Sanki.

  This might seem to be a surprising result, but by the mid 1960s KTC is known to have had at least three major contracts requiring adjustable wrenches, for customers including Nissan, Fuller Tool, and Sears Roebuck. The excess demand from these contracts, in addition to the normal sales volume to other customers, may have greatly exceeded the production capacity of KTC's factory.

Based on the evidence here, we will assume that KTC made extensive use of contract production for adjustable wrenches, with Hokuyo Sangyō as the primary outside producer, but possibly with others as well.

We will update this section as new information becomes available.

Understanding "Maru" (丸形) and "Spear Type" (ヤリ形) Jaw Styles

Early open-end wrenches were typically designed with approximately round heads, but eventually some manufacturers developed wrenches with slightly elongated jaws that became known as "spear type". The JIS B4630 standard eventually accepted "spear type" jaws as a sub-type designated by an "S" suffix, and afterwards wrenches were described as either "maru" or "spear type".

Following a similar path, early adjustable wrenches were typically designed with approximately round heads, then in the mid 1960s KTC developed a "spear type" variant with the goal of changing the weight and balance of the head. However, unlike the case for open-end wrenches, the JIS B4604 standard did not recognize "spear type" jaws as an offical variant, but left the design choice to the manufacturer.

To illustrate the differences between the "maru" and "spear type" designs, we have taken photographs of wrench heads and annotated them with a circumscribed circle just outside the jaws of the wrench.

Our first example is a typical "maru" design for Japanese adjustable wrenches.

Fig. 7 shows the jaws of the "Strong HIT" 200mm Adjustable Wrench with a circumscribed circle.

Note that the outline of the fixed jaw closely tracks the red circle, and that the circle covers most (but not all) of the wrench head.

Our second example is an early "spear type" design made by KTC for Fuller Tool.

Fig. 8 shows the jaws of the Fuller "KTC" 12 Inch Adjustable Wrench with a circumscribed circle.

Note that the outline of the fixed jaw has less curvature and deviates from the circle, and that the circle extends well beyond of the wrench head.

We can see that the elongated jaws of this design require a relatively larger circumscribing circle.

Stylistic Generations of Adjustable Wrenches

KTC's adjustable wrenches went through a number of production changes over the years, and the following table is an attempt to summarize the changes, with estimated production dates.

In the table we have identified six stylistic generations, beginning with the early Nissan OEM contract production by Yamaco around 1953 and extending to production shared with Sanki in the late 1970s to 1980s. Additional generations may be needed for later changes.

KTC "Nissan" 200mm Adjustable Wrench

This next figure shows a first-generation KTC adjustable wrench, made under the Nissan OEM contract but with production by Yamaco.

Fig. 9 shows a KTC 200mm adjustable wrench, marked with the Nissan logo and "Boron Steel" forged into the front, with "KYOTO" and "K.T.C." plus the KTC-Double-Circle logo forged into the back.

The wrench is also marked with the JIS logo and "Y.K" forged into the back.

The lower inset shows a close-up of the open jaws, illustrating the rounded transition at the corner of the fixed jaw and the inset convex cutaway of the moveable jaw. Note also the full width of the tailpiece of the moveable jaw.

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

The finish appears to be nickel plating, with minor losses due to rust.

We removed the pin securing the worm gear and verified that it is threaded on the inside end.

This wrench has a rather complex history, which we can begin to explore by examining the markings.

The front of the wrench seems relatively simple, with the Nissan logo indicating an OEM wrench probably intended for an in-vehicle tool kit. The "Boron Steel" marking is a bit unusual though, as boron is not a common alloying element, but a small amount of boron (less than one percent) can increase the hardness of carbon steel.

The back of the wrench offers a big surprise though, with "KYOTO" and "K.T.C." flanking the "Nijūmarukyo" logo, the same markings found on KTC's standard production! This kind of double-branding is rather unusual for contract production, as usually both the customer and the manufacturer would prefer not to draw attention to the maker.

The surprise continues with the JIS-Circle marking. The JIS industrial standards were very new in the early 1950s, and this wrench was probably first JIS-certified tool to appear in a mass-market vehicle tool kit.

One more surprise can be found in the small "Y.K" code the the right of the JIS mark. This is the JIS ID code for Yamaco, indicating that this particular wrench was actually made by Yamaco.

Our hypothesis is that when KTC first signed the OEM contract with Nissan, KTC itself had not yet received JIS certification for adjustable wrenches, and as a result Yamaco was brought in as the contract producer. Yamaco received JIS certificate 2356 for adjustable wrenches in June of 1953, and presumably the Nissan production would have begun sometime after that.

KTC received JIS certificate 3523 in November of 1954 and presumably would have begun its own production of the Nissan OEM wrenches shortly afterwards. KTC's Nissan wrenches are nearly identical to the Yamaco example here except for the omission of the "Y.K" marking.

The Nissan OEM wrenches were produced in great quantities and are still quite common today (2024) 60 to 70 years later. Observations of online photographs show that the Yamaco and KTC variants are both common, suggesting that Yamaco continued as a production partner.

Pliers

KTC began producing combination pliers in the early 1950s and received JIS certificate 3487 for class B4614 on October 21, 1954.

KTC [JP-200] 200mm (8 Inch) Combination Pliers

Fig. 10 shows a pair of KTC [JP-200] 200mm (8 inch) combination pliers, stamped with "95" and the JIS-Circle logo on the front, with "Pat." and "399268" plus the KTC-Oval logo forged into the back.

The lower inset shows the back side of the pliers in the wider opening position, partially revealing one of the circular wells for the slip-joint mechanism.

The top inset shows a side view of the pliers, illustrating the raised dimples of the gripping pattern.

The overall length is 8.0 inches, and the finish is chrome plating with polished jaws.

These pliers were listed as model SP08 in early KTC catalogs, but as JP-200 in later editions.

The patent marking refers to KTC's utility model ("petty") patent M399268, registered on January 23, 1953. The patent describes a slip-joint mechanism in which a raised oval land forged into one handle operates within overlapping circular wells in the other handle, remaining locked in one well when the angle between the handles is small, but slipping between the wells (to change the adjustment) when the handles are opened wide.

It's the same idea as a standard slip-joint mechanism, but with the flattened bolt replaced by a much wider oval land, thereby spreading the reaction forces over a broader surface. The screw serves only to hold the pliers together and does not bear any force when the pliers are gripping an object.

KTC's patent is basically identical to the 1939 Palmer patent 2,152,563, which was used by the Palmer Brothers Company for a moderately successful line of "Welloct" (well-locked) pliers in the 1940s and 1950s. The Palmer patent would have expired in 1956.

KTC JPS-150 150mm (6 Inch) Slip-Joint Combination Pliers

Fig. 11 shows a pair of KTC JPS-150 150mm (6 inch) combination pliers, stamped with the KTC-Oval logo and model number near the pivot.

The pliers are also stamped with the JIS-Circle logo and a K-Circle logo on the front, with "579037" and "Japan" on the back.

The top inset shows a side view of the pliers, illustrating the chevron (or herringbone) gripping pattern.

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

The K-Circle logo indicates production by Kyoto Kōki, which received JIS certificate 579037 in 1979 for combination pliers.

These pliers use a standard slip-joint adjustment mechanism.

Pipe Wrenches

By the mid 1960s KTC was offering heavy-duty (Ridgid pattern) pipe wrenches, the result of an intensive development program initiated at the request of Fuller Tool.

The company later offered Stillson-pattern pipe wrenches as well.

KTC [PW-300] 300mm (12 Inch) Heavy-Duty Pipe Wrench

Fig. 12 shows a KTC [PW-300] 300mm (12 inch) heavy-duty pipe wrench, marked with "K.T.C." and "Top Quality" cast into the front, with "K.T.C." and the JIS-Circle+H logo cast into the back side.

The moveable jaw is marked with "Drop Forged" and the KTC-Oval logo forged into one side, with graduation marks for the opening size on the opposite side.

The overall length is 10.6 inches closed and 12.9 inches fully extended. The finish is plain steel and red paint.

KTC received JIS certification for pipe wrenches sometime before 1972, but the exact date is not yet known.

The absence of a "Japan" marking suggests that this wrench was originally sold into the domestic market.

Production for Toyota Motors

KTC had a production contract with Toyota Motors at the start of its operations in 1950, and Toyota remained an important customer for many years.

KTC is known to have produced open-end wrenches and pliers for Toyota, but it's an open question as to whether the company also made adjustable wrenches for Toyota. We are currently trying to find information and examples (if any) of early Toyota adjustable wrenches.

Later Toyota adjustable wrenches were made by Toho Kōki, and an example can be seen as the Toyota Motor 250mm Adjustable Wrench.

Our current hypothesis is that Toyota adjustable wrenches made by KTC (if they exist) look substantially the same as the example from Toho Kōki, and can be distinguished by having inside threads on the pin holding the worm gear. If any of our readers have an example of such a wrench, please let us know via email.

[KTC] Toyota Motor 14x17mm Open-End Wrench

Fig. 13 shows a Toyota Motor 14x17mm open-end wrench with recessed oval panels, marked with "Toyota Motor" and the metric sizes forged into the front, with "Nickel-Chrome-Vanadium" and "Japan" forged into the back side.

The overall length is 6.4 inches, and the finish is chrome plating with polished faces.

The recessed oval panels of this wrench closely resemble the illustration on page 8 [External Link] of the 1966 KTC catalog, which shows the company's line of JIS-certified open-end wrenches. The catalog description notes that the wrenches were made of nickel chrome vanadium alloy steel, the company's preferred alloy steel in the 1950s and 1960s.

The catalog reference provides a production estimate in the 1960s for this wrench.

Contract production for Fuller and Award also used this design with recessed oval panels and forged-in markings, and it's possible that the wrenches made for Fuller and Award might have been made of the same steel, as it would be valid to mark it as "Chrome Vanadium".

[KTC] Toyota Motor 200mm (8 Inch) Combination Pliers

Fig. 14 shows a pair of Toyota 200mm (8 inch) combination pliers, stamped with "Toyota" and "Japan" on the front, with "Pat." and "399268" plus the KTC-Oval logo forged into the back side.

The top inset shows a side view of the pliers, illustrating the raised dimples of the gripping pattern.

The overall length is 8.0 inches, and the finish is chrome plating with polished faces.

The patent describes a slip-joint mechanism in which a raised truncated cylindrical projection forged into one handle engages a circular recess on the other handle, thereby relieving all sheer stress from the connecting screw.

The 1963 catalog has an illustration of this patent, but the catalog shows the patent number as "399238" rather than the "399268" forged into the pliers. The published announcement document for the patent turns out to be 27-7597, issued on January 23, 1953.

The design shown in the patent is nearly identical to the 1939 Palmer patent 2,152,563, which was used by the Palmer Brothers Company for their line of "Welloct" ("well-locked") pliers.

Production for Nissan

KTC supplied JIS-certified adjustable wrenches to Nissan beginning around 1953, with initial production outsourced to Yamaco.

Production for Fuller and Award Brands

The figures in this section show examples of tools produced by KTC for the Fuller Tool Company and its Award subsidiary. Award Tool was founded in 1963 as a reseller of hand tools, and from 1965 onward operated as a subsidiary of Fuller. (It's possible that KTC might have provided production for Award while it was still independent, but we do not have any specific evidence.)

Wrenches

Wrenches made for Fuller and Award have been observed in three styles as noted in the list below. The sections will offer production date estimates partly based on catalog references, but with a large degree of uncertainty due to a lack of early catalogs.

More discussion on these wrenches can be found in the section on Fuller Wrenches.

• Recessed Oval Panels

  Wrenches with recessed oval panels are believed to represent the earliest production period and were likely made in the 1960s. Wrenches in this style were made with forged-in markings, and the known examples were marked for chrome vanadium steel.

  The open-end wrenches of this generation closely resemble KTC's own production, as illustrated on page 8 [External Link] of the 1966 KTC catalog.

• Raised Oval Panels

  The second style was characterized by raised oval panels and stamped markings. Production of this style probably began in the late 1960s and continued through the 1970s, and possibly beyond.

  Wrenches in this style were marked either as "Drop Forged" or "Forged Alloy", but no specific alloy references are known. The less specific alloy references may indicate that this style was intended for less expensive wrenches.

  Another characteristic of this style is a forged-in "Fx" manufacturing code, with the "F" prefix believed to indicate a Fuller-specific forging die.

• Raised Parallelogram Panels

  The third style is characterized by raised paralleogram panels and stamped markings, with production commencing in the late 1970s. The earliest published reference is in a 1979 catalog, which can be seen as the Catalog Listing of Fuller Parallelogram Wrenches.

  Wrenches in this style were marked with a specific alloy as either "Chrome Vanadium" or "Chrome Molybdenum".

  This style has a forged-in manufacturing code of the form "Ux".

The figures below will show examples of the different styles.

[KTC] Fuller 11/16x3/4 Open-End Wrench

Fig. 15 shows a Fuller 11/16x3/4 open-end wrench with raised oval panels, stamped with "Fuller" and the fractional sizes on the front panel, with "Drop Forged" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in "F24" code visible at the right.

The overall length is 7.3 inches, and the finish is chrome plating with polished faces.

[KTC] Fuller 3/4x7/8 Open-End Wrench

Fig. 16 shows an early Fuller 3/4x7/8 open-end wrench with recessed oval panels, marked with "*Fuller*" and "Chrome Vanadium" plus the fractional sizes forged into the front, with "Drop Forged" and "Japan" plus the KTC-Oval logo forged into the back.

The overall length is 8.6 inches, and the finish is chrome plating, with extensive losses due to wear and rust.

This wrench closely resembles the illustration on page 8 [External Link] of the 1966 KTC catalog, which is consistent with our estimate of production in the 1960s.

[KTC] Fuller/Award 15/16x1 Open-End Wrenches

The next figures show two generations of Fuller/Award 15/16x1 inch wrenches.

Fig. 17 shows an Award 15/16x1 open-end wrench with recessed oval panels, marked with "Chrome Vanadium" and the fractional sizes forged into the shank, with "Drop Forged" and "Japan" plus the KTC-Oval logo forged into the back side.

The overall length is 11.9 inches, and the finish is chrome plating.

The KTC-Oval logo indicates that the wrench was produced by the Kyoto Tool Company.

Fig. 18 shows a Fuller 15/16x1 inch open-end wrench with parallelogram panels, stamped with "Fuller" and the fractional sizes on the front panel, with "Chrome Molybdenum" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in code "U02" visible at the right.

The overall length is 11.9 inches, and the finish is chrome plating with polished faces.

[KTC] Fuller 13x15mm Open-End Wrench

Fig. 19 shows a Fuller 13x15mm open-end wrench with raised oval panels, stamped with "Fuller" and the metric sizes on the front panel, with "Drop Forged" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in "F35" code visible at the right.

The overall length is 5.9 inches, and the finish is chrome plating with polished faces.

[KTC] Fuller 17x19mm Open-End Wrench

Fig. 20 shows a Fuller 17x19mm open-end wrench with raised oval panels, stamped with "Fuller" and the metric sizes on the front panel, with "Drop Forged" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in "F79" code visible at the right.

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

[KTC] Award 3/8 Combination Wrench

Fig. 21 shows an Award 3/8 combination wrench with recessed oval panels, marked with "Award" and "Chrome Vanadium" plus the fractional size forged into the shank, with "Drop Forged" and "Japan" plus the KTC-Oval logo forged into the back side.

The overall length is 4.6 inches, and the finish is chrome plating with polished faces.

[KTC] Fuller/Award 7/16 Combination Wrenches

The next figures show two generations of the Fuller/Award 7/16 combination wrenches.

Fig. 22 shows an Award 7/16 combination wrench with recessed oval panels, marked with "Award" and "Chrome Vanadium" plus the fractional size forged into the front panel, with "Drop Forged" and "Japan" plus the KTC-Oval logo forged into the back panel.

The overall length is 5.5 inches, and the finish is chrome plating with polished faces.

Fig. 23 shows a Fuller 7/16 combination wrench with raised oval panels, stamped with "Fuller" and the fractional size on the front panel, with "Forged Alloy" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in code "F4" visible at the left.

The overall length is 5.0 inches, and the finish is chrome plating with polished faces and ends.

[KTC] Fuller 1/2 Combination Wrench

Fig. 24 shows a Fuller 1/2 combination wrench with raised oval panels, stamped with "Fuller" and the fractional size on the front panel, with "Forged Alloy" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in code "F6" visible at the left.

The overall length is 5.5 inches, and the finish is chrome plating with polished faces and ends.

[KTC] Fuller/Award 5/8 Combination Wrenches

The next figures show three generations of the Fuller/Award 5/8 combination wrenches.

Fig. 25 shows an Award 5/8 combination wrench with recessed oval panels, marked with "Award" and "Chrome Vanadium" plus the fractional size forged into the shank, with "Drop Forged" and "Japan" plus the KTC-Oval logo forged into the back side.

The overall length is 7.8 inches, and the finish is chrome plating, with losses due to wear.

Fig. 26 shows a Fuller 5/8 combination wrench with raised oval panels, stamped with "Fuller" and the fractional size on the front panel, with "Forged Alloy" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in "F6" code visible at the left.

The overall length is 7.0 inches, and the finish is chrome plating with polished faces and ends.

Fig. 27 shows a Fuller 5/8 combination wrench with raised parallelogram panels, stamped with "Fuller" and the fractional size on the front panel, with "Chrome Molybdenum" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in "U0" code visible at the left.

The overall length is 7.8 inches, and the finish is chrome plating with polished faces and ends.

[KTC] Fuller 11/16 Combination Wrench

Fig. 28 shows a Fuller 11/16 combination wrench with raised parallelogram panels, stamped with "Fuller" and the fractional size on the front panel, with "Chrome Vanadium" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in "U1" code visible (upside-down) at the left.

The overall length is 8.6 inches, and the finish is chrome plating with polished faces and ends.

[KTC] Fuller 3/4 Combination Wrench

Fig. 29 shows a Fuller 3/4 combination wrench with raised parallelogram panels, stamped with "Fuller" and the fractional size on the front panel, with "Chrome Molybdenum" and "Japan" plus the KTC-Oval logo on the back panel.

The back side of the shank also has a forged-in "U4" code visible at the left.

The overall length is 9.5 inches, and the finish is chrome plating with polished faces and ends.

Other Tools

In addition to wrenches, KTC is known to have supplied Fuller with adjustable wrenches, pipe wrenches, and bolt cutters.

KTC's Kyoto Kōki subsidiary may have supplied Fuller with slip-joint pliers, but we're still gathering evidence to show a connection. In contrast to the case for wrenches, no examples of Fuller pliers have been found with a "KTC" marking.

[KTC] Fuller No. 12 12 Inch Adjustable Wrench

Fig. 30 shows a Fuller No. 12 12 inch adjustable wrench, marked with "Fuller No. 12" and "Chrome Alloy" forged into the front, with "Full Drop Forged" forged into the back side.

The back side is also marked with the KTC-Oval logo and "JAPAN" forged along a curved arc near the hanging hole.

The lower inset shows a close-up of the open jaws, illustrating the rounded corner of the fixed jaw and the inset convex cutaway of the moveable jaw.

The overall length is 12.0 inches, and the maximum opening is 1.4 inches. The finish is chrome plating with polished faces.

We were able to remove the pin securing the worm gear on this wrench and noted that it is threaded on the inside end.

This wrench is a nearly perfect embodiment of the "KTC Style" of adjustable wrenches as expressed on page 11 [External Link] of the 1966 KTC catalog. Note in particular the details of the jaw construction, the full width of the tailpiece of the moveable jaw, and the absence of a ridge around the hanging hole.

KTC is known to have relied heavily on Hokuyo Sangyō ("Sanki") for production of adjustable wrenches, but we believe that this wrench is an example of KTC's own production. This conclusion is based on the close match of all features with the 1966 catalog illustration and the relatively large hanging hole compared to Sanki.

In addition, the presence of the KTC-Oval logo on a Fuller wrench strongly suggests KTC production, though of course the company's production partners were authorized to replicate the logo. There are numerous examples of Fuller wrenches made by and marked with "Sanki", and if this wrench had been made by Sanki, it probably would have been marked that way.

Production for Sears Roebuck

KTC supplied tools to Sears Roebuck for several of its brands, including "Sears", "Companion", and "Craftsman". Contract production for Sears was marked with a "BF" code.

Tools in the "BF" series were introduced in 1964 and KTC was involved from the beginning with production of carbon-steel forged wrenches, which were made as copies of Dunlap wrenches from the mid to late 1950s. Early production also included adjustable wrenches.

A more extensive discussion of the development of the "BF" series can be found in our article on Distributor "BF".

We recently (2024) discovered that prior to the start of the "BF" series, KTC and Toho Kōki provided "Dunlap" brand adjustable wrenches to Sears in 1962 as part of a trial order. (Sears sometimnes ran test marketing experiments before deciding on a new supplier.) The Dunlap wrenches were apparently well received by the market, and the "BF" series was launched shortly afterwards.

Carbon Steel Wrenches

Sears carbon steel wrenches were one of their most popular products and were available in open-end, combination, and box-end styles.

Additional examples can be seen in the section on Sears Carbon Steel Wrenches in our article on later Craftsman tools.

[KTC] Sears "BF" 9/16x5/8 Open-End Wrenches

The next figures show two generations of the Sears "BF" 9/16x5/8 wrench, with minor differences in the markings and length.

Fig. 31 shows an early Sears "BF" 9/16x5/8 open-end wrench with depressed panels, marked with "Sears" and the fractional sizes forged into the front panel, with "Drop Forged" between "B.F" and "Japan" forged into the back panel.

The top inset shows a side view of the wrench, with traces of the trimming operation visible on the edge.

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

This wrench is marked with the first generation variant of the KTC Standard Forged Markings, which indicates production by KTC for the Sears "BF" contract. Note that in this example the "BF" and "Japan" markings are split by "Drop Forged", and the back panel doesn't repeat the size markings.

The first generation marking suggests production from 1964 to the mid 1960s.

Fig. 32 shows a later Sears "BF" 9/16x5/8 open-end wrench with depressed panels, marked with "Sears" and the fractional sizes forged into the front panel, with "Drop Forged" and "BF Japan" plus the fractional sizes forged into the back panel.

The top inset shows a side view of the wrench, illustrating the smoothly finished and polished edge of the wrench.

The overall length is 6.4 inches, and the finish is chrome plating with polished faces.

This wrench is marked with the third generation variant of the KTC Standard Forged Markings. which indicates production by KTC for the Sears "BF" contract. Note that the "BF" and "Japan" markings are joined together, and the size markings are repeated on the back panel.

The third generation marking suggests production from the mid 1970s onward.

Sears "BF" 5/8 Combination Wrenches

The next figures show two generations of the Sears "BF" 5/8 combination wrench, with minor differences in the markings.

Fig. 33 shows an early Sears 5/8 combination wrench with depressed panels, marked with "Sears" and the fractional size forged into the front panel, with "Drop Forged" between "B.F" and Japan" forged into the back side.

The top inset shows a side view of the wrench. Note that the edge of the shank has been ground smooth, but a few traces of the trimming process still remain.

The overall length is 7.0 inches, and the finish is chrome plating with polished faces.

This wrench has an early variation of the KTC Standard Forged Markings with "B.F" and "Japan" on opposite ends of the back panel.

Fig. 34 shows a somewhat later Sears 5/8 combination wrench with depressed panels, marked with "Sears" and the fractional size forged into the front panel, with "Drop Forged" and "BF Japan" plus the fractional size forged into the back side.

The top inset shows a side view of the wrench. Note that the edge of the shank has been ground smooth, and the edges of the open-end are rounded and polished.

The overall length is 7.0 inches, and the finish is chrome plating with polished faces.

The KTC Standard Forged Markings identify this wrench as production by KTC for the Sears "BF" contract.

These wrenches closely resemble the Dunlap "LC" 5/8 Combination Wrench shown in another article, strongly suggesting that the Sears "BF" wrenches were made as intentional copies.

[KTC] Sears "BF" 9/16x5/8 Offset Box-End Wrench

Fig. 35 shows a Sears 9/16x5/8 offset box-end wrench with depressed panels, marked with "Sears" and the fractional sizes forged into the front panel, with "Forged" and "BF Japan" plus the fractional sizes forged into the back panel.

The overall length is 9.4 inches, and the finish is chrome plating, with losses due to wear and rust.

This wrench can be identified as production by KTC based on a display in KTC's tool museum, which shows a wrench closely resembling this example identifed as contract ("OEM") production for Sears. The wrench in the exhibit has the same distinctive production characteristics, including the short horizontal sections joining the box ends.

This wrench was designed as an intentional copy of Dunlap offset box wrenches made by Lectrolite, an example of which can be seen as the Dunlap "LC" 3/8x7/16 Offset Box-End Wrench. Note the precisely formed depressed panels with crisp forged-in markings, a hallmark of KTC's production. The marking for "BF Japan" is made with a smaller font and placed to the right of the "Forged" marking.

We will refer to the marking style of this wrench as the KTC Standard Forged Markings and will use this to identify other examples of KTC's production.

Adjustable Wrenches

[KTC] Dunlap "Japan" 6 Inch Adjustable Wrench

We recently (2024) discovered that in 1962 Sears placed a trial order for "Dunlap" brand adjustable wrenches from its prospective Japanese suppliers. We haven't found any mention of Japanese imports for Dunlap in the catalogs, and presumably these wrenches were sold only in stores.

Fig. 36 shows a Dunlap 6 inch adjustable wrench, marked with the Dunlap oval logo and "Chrome" over "Alloy Steel" forged into the shank, with "Full Drop Forged" and "Japan" forged into the back side.

The center inset shows the construction of the jaws. Note the rounded transition at the corner of the fixed jaw, with a corresponding inset convex cutaway on the moveable jaw.

The overall length is 6.1 inches and the maximum opening is 0.8 inches. The finish is chrome plating with polished faces.

We verified that the pin securing the worm gear is threaded on the inside end. However, it wasn't easy to remove the pin — the threads push the head of the pin only slightly beyond the edge of the wrench, and we had to grasp the pin with needlenose pliers to pull it out.

This wrench has been identified as part of a trial order placed by Sears in 1962 and imported by the Fuller Orient Corporation. At that time Fuller's primary manufacturing partners were KTC and Toho Kōki, and the inside threads on the pin of this wrench identify KTC as the maker.

Note the round or "maru" outline of the jaws in the center inset. In later years KTC adopted a "spear-type" outline, and this wrench will help us narrow the date estimate for the change.

The distinctive stacked "Chrome/Alloy Steel" marking is a production characteristic believed to be unique to KTC for its 6 inch adjustable wrenches. This same marking has also been observed on Sears brand 6 inch adjustable wrenches.

[KTC] Sears [30870] "BF" 6 Inch Adjustable Wrenches

The next figures show two generations of the Sears [30870] 6 inch adjustable wrench, both identified as production from KTC but with differences in the features.

Fig. 37 shows an early Sears [30870] 6 inch adjustable wrench, marked with "Sears" and "Chrome" over "Alloy Steel" forged into the front, with "Full Drop Forged" and "BF Japan" forged into the back.

The lower inset shows a close-up of the fully open jaws, illustrating the rounded corner of the fixed jaw and the corresponding inset convex cutaway of the moveable jaw.

The overall length is 6.1 inches and the maximum opening is 0.8 inches. The finish is chrome plating with polished faces, with some losses due to rust.

The wrench is not marked with a model number, but the early catalogs listed the 6 inch size as model 30870.

The construction of this wrench is nearly identical to the [KTC] Dunlap "Japan" 6 Inch Adjustable Wrench, and the presence of the distinctive stacked "Chrome/Alloy Steel" marking confirms KTC as the maker.

The pin holding the worm gear of this wrench is frozen, so we were not able to confirm the use of inside threads, but based on other details we are confident that the wrench was made by KTC.

Note the round or "maru" outline of the jaws in the center inset. In later years KTC adopted a "spear-type" outline, and this wrench helps us narrow the date estimate for the change.

Continuity with the earlier Dunlap example plus the use of a "maru" outline and a ridge around the hanging hole lead to an early date estimate of 1964-1965 for this example.

Fig. 38 shows a somewhat later Sears [30870] 6 inch adjustable wrench, marked with "Sears" and "Chrome" over "Alloy Steel" forged into the front, with "Full Drop Forged" and "BF Japan" forged into the back.

The lower inset shows a close-up of the fully open jaws. Note the rounded corner of the fixed jaw, the inset convex cutaway in the moveable jaw, and the full width at the end of the tailpiece.

The overall length is 6.0 inches and the maximum opening is 0.8 inches. The finish is chrome plating with polished faces, with minor spots of corrosion.

The wrench is not marked with a model number, but based on the catalogs would have been model 30870.

The markings on this wrench are nearly identical to the Early Sears "BF" 6 Inch Adjustable Wrench shown above, and the presence of the distinctive stacked "Chrome/Alloy Steel" marking confirms KTC as the maker.

We were not able to remove the pin holding the worm gear, but the walls of the bore are smooth, confirming the use of inside threads as expected for KTC.

Although the markings of this wrench match the earlier Sears 6 inch wrench, the construction differs in the use of elongated "spear type" jaws and a plain hanging hole. In these aspects the wrench is nearly identical to the Sears "BF" 8 Inch Adjustable Wrench shown below, and also matches the illustration on page 11 [External Link] of the 1966 KTC catalog.

The absence of a model number suggests production before 1970, when Sears began requiring model number markings. The "spear type" jaws and plain hanging hole suggest production in 1966 or later, as earlier production by KTC for Sears had "maru" outline jaws and a ridge around the hanging hole.

The reader may wish to review the Dunlap "Japan" 6 Inch Adjustable Wrench, the Early Sears "BF" 6 Inch Adjustable Wrench, and the present example as a progression, as these represent three generations of KTC production for Sears.

[KTC] Sears [30871] "BF" 8 Inch Adjustable Wrench

Fig. 39 shows a Sears [30871] 8 inch adjustable wrench, marked with "Sears" and "Chrome Alloy Steel" forged into the shank, with "Full Drop Forge" and "BF Japan" on the back side.

The lower inset shows a close-up of the fully open jaws. Note the rounded corner of the fixed jaw, the inset convex cutaway in the moveable jaw, and the full width at the end of the tailpiece.

The overall length is 7.9 inches, and the finish is chrome plating with polished faces.

The wrench is not marked with a model number, but based on the catalogs would have been model 30871.

This wrench closely resembles the illustration on page 11 [External Link] of the 1966 KTC catalog, in particular with the jaw details noted above and the absence of a ridge around the hanging hole. Note also the elongated "spear type" jaw outline.

Another construction characteristic noted for this wrench is that the pin securing the worm gear is threaded on the inside end.

In addition to closely matching the KTC catalog illustration, this wrench is nearly identical (except for markings) to the [KTC] Fuller No. 12 Adjustable Wrench displayed in an earlier figure. The additional comparison with the Fuller example provides strong evidence that this wrench was produced by KTC.

The absence of a model number suggests production from 1964-1969, after which Sears began requiring model number markings. The "spear type" outline of the jaws and plain hanging hole suggest production in 1966 or later, as earlier production by KTC for Sears had "maru" outline jaws and a ridge around the hanging hole.

Pipe Wrenches

KTC began supplying pipe wrenches for the Sears "BF" series in 1968 following an intensive development program.

[KTC] Sears 30852 "BF" 14 Inch Heavy-Duty Pipe Wrench

In 1968 Sears offered Japanese heavy-duty pipe wrenches in models 30851 and 30852, with sizes 10 and 14 inches respectively. This next figure shows an example of the larger model.

Fig. 40 shows a Sears 30852 14 inch heavy-duty (Ridgid pattern) pipe wrench, marked with "Sears" and "Heavy Duty" plus the model number cast into the shank, with the same markings plus "14" and "Japan" cast into the back side.

The jaw is marked "Drop Forged" (partly obscured) with the KTC-Oval logo and "BF" forged into the recessed panel, as shown in the small inset.

The overall length is 12.8 inches closed and approximately 15.3 inches fully extended. The finish is plain steel and red paint.

For this wrench we don't have to guess the manufacturer, as KTC was thoughtful enough to place their well-known logo on the moveable jaw.

By 1978 Sears was offering Japanese heavy-duty pipe wrenches under its "Craftsman" brand, and although we don't have an example available, we strongly suspect that KTC was the maker of the Craftsman pipe wrenches as well.

[KTC] Sears [30884] "BF" 18 Inch Stillson-Pattern Pipe Wrench

By 1969 KTC was supplying Stillson-pattern pipe wrenches to Sears in a distinctive design with a paneled jaw carrier and a hidden spring.

Fig. 41 shows a Sears [30884] 18 inch Stillson-pattern pipe wrench, marked with "Sears" forged into the handle, with "Japan BF" forged into the back side.

The overall length is 15.9 inches closed and approximately 18.5 inches fully extended. The finish is plain steel and red paint.

The wrench is not marked with a model number, but based on the catalogs would have been model 30884.

The absence of a model number suggests production before 1970, and the first catalog listing in 1969 leads to a 1969 production date estimate for this wrench.

This wrench can be recognized as the Sears second-generation Stillson pattern by the paneled jaw carrier, the absence of external leaf springs, and the forged-in "Sears" marking. (These wrenches were also made with forged-in "Companion" brand markings.)

The Fuller version of this wrench was identical except for the markings, which typically included the KTC-Oval logo. By 1971 KTC itself was offering this model on page 20 [External Link] of its catalog, and the illustration noted a JIS "H" certification.

Craftsman Combination Wrenches

1n 1969 KTC began supplying Craftsman combination for the Sears "BF" series, which were the first Craftsman-branded tools in the series.

[KTC] Craftsman "BF" 5/8 Combination Wrench

The next figure shows an early example of KTC's production for the Craftsman brand.

Fig. 42 shows a Craftsman "BF" 5/8 combination wrench with raised panels, stamped with the "=Craftsman=" logo and fractional size on the front panel, with "Chrome Molybdenum" and "BF Japan" plus the fractional size on the back panel.

The shank is also marked with a forged-in "C0" code, as seen in the lower inset.

The top inset shows a side view of the wrench. Note the rounded and polished side of the open end, an extra finishing touch provided by this maker.

The overall length is 7.8 inches, and the finish is chrome plating.

The forged-in "C0" code indicates that this wrench was produced by KTC for the Sears Craftsman brand.

The absence of a model number on this wrench suggests production before 1970. KTC's published history states that production of Craftsman combination wrenches began in 1969, suggesting that this is an early example.