| Alloy Artifacts |
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.
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.
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.
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.
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.]
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.
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.
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.
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.
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.
By 1969 KTC was supplying "Craftsman" combination wrenches, an important milestone as the first "BF" series tool for the Craftsman brand.
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.
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.
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.
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.
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.
In 1995 the company released the Nepros line of "Mirror" tools.
In 2003 the KTC Manufacturing Technology Museum was opened to the public.
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.
| Text Mark or Logo | Reg. No. | First Use | Date Filed | Date Issued | Notes and Examples |
|---|---|---|---|---|---|
 |
1,663,191 | 01/01/1970 | 03/05/1990 | 11/05/1991 | "KTC" in an oval.
Published 8-13-1991. |
| Nepros | 2,178,828 | 11/01/1994 | 06/26/1995 | 08/04/1998 | "Nepros" in stylized text.
Serial 74-694,179. Published 7-9-1996. |
| KTC | 5,567,556 | 01/01/1970 | 08/16/2016 | 09/25/2018 | "KTC" in a stylized form.
Serial 79,204,588. Published 7-10-2018. |
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.
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.
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.
Fig. 1 shows the KTC-Oval logo as it was presented for trademark #1,663,191.
![[KTC-Oval Logo]](Photos/tools/ktc_ktc-oval_logo.jpg){kind=logo}
Fig. 2 shows the KTC-Oval logo, as stamped on a Fuller 3/4 combination wrench shown in a later figure.
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.
![[KTC Standard Forged Markings, Early Type]](Photos/tools/ktc_standard_forged_markings_early.jpg)
Fig. 3 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.
![[KTC Standard Forged Markings]](Photos/tools/ktc_standard_forged_markings_joined.jpg)
Fig. 4 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.
![[KTC-Oval Logo]](Photos/tools/ktc_standard_forged_markings_cropped.jpg){kind=small}
Fig. 5 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.
Photographs and observations of particular tools are based on items in the Alloy Artifacts Collection.
| Catalog | Year | Notes |
|---|---|---|
| Hand Tool | 1955 | Price list in Japanese. 27 pages.
Available for Download [External Link] from ITCL. Notes JIS numbers on pages with certified tools. |
| Catalog No. 8 | 1966 | Catalog in English. 20 pages.
Address listed as Shimotoba, Fushimi-ku, Kyoto, Japan. Available for Download [External Link] from ITCL. Illustrates open-end wrenches with recessed oval panels and forged-in markings. Illustrates combination wrenches with parallelogram panels. Illustrates adjustable wrenches with spear-type jaws, rounded inside corner, and plain hole. |
| KTC Hand Tools | 1977 | Catalog in English. Dated 77.9 on back cover. 32 pages.
Available for Download [External Link] from ITCL. Illustrates adjustable wrenches with angled inside corner, ridge around hanging hole. |
| Catalog No. 20 | 1983 | Catalog in Japanese. 69 pages.
Available for Download [External Link] from ITCL. |
Currently all of our examples of KTC's tools are contract production for other brands, in particular the Fuller Tool Company and its Award subsidiary. 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.
Currently we don't have any KTC-branded adjustable wrenches to display, but we're adding this section 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.
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.
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.
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 type" (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.
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.
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.
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.
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.
| Date | Logo Style | Transition | Jaw Style | Hole Style | Notes and Examples |
|---|---|---|---|---|---|
| 1953-1954 | Nijumarukyo | Rounded | Maru | Plain | Nissan OEM by Yamaco
KTC "Nijumarukyo" OEM for Nissan |
| 1954-1959 | Nijumarukyo | Rounded | Maru | Plain | Nissan OEM by KTC
KTC "Nijumarukyo" OEM for Nissan |
| 1960-1965 | KTC-Oval | Rounded | Maru | Plain | Hypothetical; no examples observed. |
| 1966-1972? | KTC-Oval | Rounded | Spear-type | Plain | Illustrated in 1966 catalog on page 11 |
| 1972-1977? | KTC-Oval | Rounded | Spear-type | Ridge | Dates uncertain, but examples observed. |
| 1977-1980s? | KTC-Oval | Angled | Spear-type | Ridge | Illustrated in 1977 catalog, observed for Sanki.
No examples observed for KTC production. |
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.
![[Toyota Motor 14x17mm Open-End Wrench]](Photos/tools/toyota_motor_oe1417mm_wrench_depressed_ncv_japan_f_cropped_inset.jpg)
Fig. 6 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".
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 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.
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.
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.
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.
![[Fuller 11/16x3/4 Open-End Wrench]](Photos/tools/fuller_oe2224_wrench_panel_ktc_f_cropped_inset.jpg)
Fig. 7A 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.
![[Fuller 3/4x7/8 Open-End Wrench]](Photos/tools/fuller_oe2428_wrench_depressed_cv_ktc_f_cropped_inset.jpg)
Fig. 7B 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.
The next figures show two generations of Fuller/Award 15/16x1 inch wrenches.
![[KTC Award 15/16x1 Open-End Wrench]](Photos/tools/award_oe3032_wrench_cv_ktc_f_cropped_inset2_gs.jpg)
Fig. 8A 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.
![[Fuller 15/16x1 Inch Open-End Wrench]](Photos/tools/fuller_oe3032_wrench_parallel_crmo_ktc_f_cropped_inset.jpg)
Fig. 8B 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.
![[Fuller 13x15mm Open-End Wrench]](Photos/tools/fuller_oe1315mm_wrench_oval_ktc_japan_f_cropped_inset.jpg)
Fig. 10 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.
![[Fuller 17x19mm Open-End Wrench]](Photos/tools/fuller_oe1719mm_wrench_oval_ktc_japan_f_cropped_inset.jpg)
Fig. 11 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]](Photos/tools/award_c12_wrench_depressed_cv_ktc_japan_f_cropped_inset2.jpg)
Fig. 13 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.
The next figures show two generations of the Fuller/Award 7/16 combination wrenches.
![[Award KTC 7/16 Combination Wrench]](Photos/tools/award_c14_wrench_depressed_cv_ktc_japan_f_cropped_inset2.jpg)
Fig. 14A 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.
![[Fuller 7/16 Combination Wrench]](Photos/tools/fuller_c14_wrench_panel_alloy_ktc_japan_f_cropped_inset2.jpg)
Fig. 14B 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.
![[Fuller 1/2 Combination Wrench]](Photos/tools/fuller_c16_wrench_panel_alloy_ktc_japan_f_cropped_inset2.jpg)
Fig. 15 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.
The next figures show three generations of the Fuller/Award 5/8 combination wrenches.
![[Award KTC 5/8 Combination Wrench]](Photos/tools/award_c20_wrench_depressed_cv_ktc_japan_f_cropped_inset2.jpg)
Fig. 16A 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.
![[Fuller 5/8 Combination Wrench]](Photos/tools/fuller_c20_wrench_combo_ktc_alloy_f_cropped_inset2.jpg)
Fig. 16B 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.
![[Fuller 5/8 Combination Wrench]](Photos/tools/fuller_c20_wrench_panel_crmo_ktc_japan_f_cropped_inset2.jpg)
Fig. 17 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.
![[Fuller 11/16 Combination Wrench]](Photos/tools/fuller_c22_wrench_combo_cv_japan_ktc_f_cropped_inset2.jpg)
Fig. 18 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.
![[Fuller 3/4 Combination Wrench]](Photos/tools/fuller_c24_wrench_combo_ktc_crmo_f_cropped_inset2.jpg)
Fig. 18B 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.
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]](Photos/tools/fuller_adj_no12_wrench_ca_ktc_japan_f_cropped_inset4_w2048.jpg)
Fig. 19 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.
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.
Production for the "BF" code began 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".
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.
The next figures show two generations of the Sears "BF" 9/16x5/8 wrench, with minor differences in the markings and length.
![[Sears BF 9/16x5/8 Open-End Wrench]](Photos/tools/sears_oe1820_wrench_depressed_bf_split_japan_f_cropped_inset2_w2048.jpg)
Fig. 20A 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.
![[Later Sears BF 9/16x5/8 Open-End Wrench]](Photos/tools/sears_oe1820_wrench_depressed_forged_bf_japan_f_cropped_inset2_w2048.jpg)
Fig. 20B 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.
The next figures show two generations of the Sears "BF" 5/8 combination wrench, with minor differences in the markings.
![[Sears BF 5/8 Combination Wrench]](Photos/tools/sears_c20_wrench_depressed_bf_split_japan_f_cropped_inset2_w2048.jpg)
Fig. 21A 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.
![[Sears BF 5/8 Combination Wrench]](Photos/tools/sears_c20_wrench_depressed_japan_bf_f_cropped_inset2.jpg)
Fig. 21B 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.
![[Sears BF 9/16x5/8 Offset Box-End Wrench]](Photos/tools/sears_db1820_wrench_offset_depressed_japan_bf_f_cropped_inset2.jpg)
Fig. 21B 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.
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.
![[Dunlap Japan 6 Inch Adjustable Wrench]](Photos/tools/dunlap_adj_6in_wrench_cas_japan_f_cropped_inset3_w2048.jpg)
Fig. 22A 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.
![[Sears 30871 BF 8 Inch Adjustable Wrench]](Photos/tools/sears_adj_8in_wrench_cas_bf_japan_f_cropped_inset3_w2048.jpg)
Fig. 22B 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.
The absence of a model number suggests production from 1964-1969, after which Sears began requiring model number markings.
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.
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.
KTC began supplying pipe wrenches for the Sears "BF" series in 1968 following an intensive development program.
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.
![[Sears 30852 BF 14 Inch Pipe Wrench]](Photos/tools/sears_30852_14in_pipe_wrench_ktc_bf_japan_f_cropped_inset3_w2048.jpg)
Fig. 23 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.
1n 1969 KTC began supplying Craftsman combination for the Sears "BF" series, which were the first Craftsman-branded tools in the series.
The next figure shows an early example of KTC's production for the Craftsman brand.
![[Craftsman BF 5/8 Combination Wrench]](Photos/tools/craftsman_c20_wrench_combo_crmo_bf_f_cropped_inset3.jpg)
Fig. 24 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.
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