Plomb Tool Company

Table of Contents

Introduction

The Plomb Tool Company was an important and innovative maker of automotive hand tools during the first half of the 20th century, growing from a modest blacksmith shop to become one of the largest producers of hand tools. Then through an odd problem with trademarks, Plomb had to change its brand name to "Proto" in 1948, leaving a legacy of Plomb-marked tools as a snapshot of early to mid-20th century tool production.

This page will look briefly at the company's history, and then show some examples of the many tools produced by Plomb.

Company History

The Plomb Tool Company had its beginning in 1907 as a small blacksmith shop in Los Angeles, operated by partners Charles Williams, Jacob Weninger, and Alphonse Plomb. Its earliest tools included items such as hand-forged chisels and punches, intended primarily for the plumbing and building trades. Relatively little is known of this phase of Plomb's history, as the type of tools produced tended to wear out with use, and may not have been even marked for identification.

By 1917 Alphonse Plomb had left Plomb Tool to go into business for himself, and in 1917 Charles Williams brought in John L. Pendleton as a partner and manager. A later article on Plomb ("KPLA" in the References section) identified Williams as the salesman-partner of the original partnership of 1907, and noted that Pendleton had acquired the interest of a deceased partner. (Presumably that would have been Jacob Weninger.)

Pendleton had previously worked as a manufacturer's agent for hardware and tool companies and had extensive knowledge of the tool business.

2209 Santa Fe Avenue

By 1920 the partnership was doing business as the Plomb Tool Manufacturing Company and made an important decision to purchase a factory at 2209 Santa Fe Avenue, the site it would occupy for many decades.

Fig. 1A. 1920 Notice of Purchase of Santa Fe Avenue Factory.

The scan in Fig. 1A shows a notice of the real estate transaction, published on page 70 of the April 25, 1920 edition of the Los Angeles Times.

The text notes the company's products as tools primarily for trades such as brick laying, carpentry, and plumbing, but also mentions "auto makers", a hint of the future importance of mechanic's tools.

After the death of John Pendleton in 1924, he was succeeded as partner and manager by his son, Morris B. Pendleton.

12-Point Box-End Wrenches

During the 1920s Plomb expanded into the automotive tools market, and its first catalogs were published in the mid 1920s.

By 1926 Plomb was offering an A-series of single-ended 12-point box wrenches, making it one of the earliest (along with P&C) companies to offer such tools. These wrenches were an important new class of tools made possible by alloy steel.

By 1928 Plomb box wrenches were available in an AD-series of double offset wrenches, with six sizes from 7/16x1/2 to 15/16x1 inch. Examples of these early models can be seen in the section on Early Box Wrenches.

Periodical Advertisements

By the late 1920s the company was advertising in some of the popular periodicals of the time, probably in order to broaden its customer base.

For example, an ad on page 90 [External Link] of the December 1928 issue of Popular Science Monthly shows a Plomb hand-forged screwdriver, with the text noting the use of special tungsten steel. The screwdrivers were constructed with a square shank running through the handle to the metal cap.

Interestingly, this 1928 ad shows the Plomb name with an inverted triangle, at a time several years before this "PLVMB" logo began to be used on tools.

Fig. 1B. 1929 Ad for Plomb Socket Set.

The scan in Fig. 1B shows an ad for the Plomb DD120 socket set, as published on page 100 [External Link] of the March, 1929 issue of Popular Science Monthly.

The text mentions the use of molybdenum steel for strength and toughness, and emphasizes the use of thin-walled 12-point sockets.

The illustration shows the tools and sockets in the popular DD120 set.

Chicago Branch Office

As early as 1930 Plomb had established a branch office in Chicago located at 627 West Washington Boulevard, and the company was listed in the 1930 Donnelley's Industrial Directory.

Plomb continued to grow rapidly during the 1930s.

Flex-Head ("Hinge") Handles

In the late 1920s Plomb became one of the first companies to introduce a flex-head drive handle for sockets, referred to as "hinge" handles in the Plomb catalogs. Plomb's design was based on the 1921 Eagle patent #1,380,643, filed by Samuel Eagle in 1920. Several examples of these tools are shown in a later section, such as the Plomb DTH Hinge Handle.

The hinge handles became very popular and other tool companies soon began to offer competing models, frequently with a slightly different head design to avoid obvious patent infringement. The most common alternate design placed the fork on the movable head rather than at the end of the handle.

Eventually some companies began offering models very similar to the Eagle design, and in the early 1930s Samuel Eagle filed a patent infringement lawsuit against the P&C Hand Forged Tool Company. In a 1935 decision (Eagle v. P&C Hand Forged Tool Co., 9 Cir., 74 F.2d 918, 920) the court found in favor of P&C, judging that the Eagle patent was invalid based on claims in several different prior patents. More information on the Eagle Lawsuit can be found in our article on P&C.

Combination Wrenches

Plomb is generally credited with being the first company to produce the modern combination wrench, a style with an open-end and box-end of the same size. Plomb announced its new wrench design in the April 25, 1933 issue of the company's newsletter, which at that time was called Sparks from the Anvil. (A copy of the newsletter can be seen on the PTP site.) The wrenches were initially available in four sizes.

Plomb even called the its new tools "Combination" wrenches, which is significant when you consider that as other companies adopted the design, the wrenches sometimes received odd names such as "TuType", "Multitype", and even "Half & Half"!

More information is available in the section on Plomb Combination Wrenches.

From Hand-Forging to Drop-Forging

As a former blacksmith operation, Plomb naturally gravitated to hand-forging for its tool production. Hand-forging uses repeated blows of a power hammer to gradually shape a tool at relatively low heat, instead of the single blow at red heat from a drop-forge hammer. Plomb tools into the mid 1930s can be recognized as hand-forged by the slight variations in thickness of the shank, although many tools of this era were ground and polished after being shaped. (In contrast, Cornwell proudly left the hammer marks on their hand-forged tools, so that everyone could see how they were made.)

And yet if we fast-forward to the post-war "Pebble Period", it's obvious that Plomb tools of this era were all drop-forged, as the pebble background and forged-in markings could only be done in a drop-forge die. So this raises the question, how and when did Plomb come to abandon its hand-forging roots in favor of drop-forging? It's an interesting issue and one that we haven't seen discussed in other Plomb-related articles.

We can make a good argument that Plomb's conversion to drop-forging was closely related to their experiment with the Wilpen Offset Box Wrenches in the 1930s. In the early 1930s Plomb became aware of the very inexpensive yet high quality box wrenches being sold through retail channels, beginning with Western Auto Supply in 1931. (See the section on Box End Wrenches in our article on Western Auto Supply for more information.)

We'd like to imagine that maybe Morris Pendleton himself wandered into the Western Auto store in Los Angeles and was stunned to find high-quality box wrenches being sold for prices that Plomb couldn't touch — and with offset box ends that would have been very difficult to make by hand-forging. But regardless of how it came about, Plomb commissioned a series of offset box wrenches from Duro Metal Products, one of Western Auto's major suppliers. These were sold as the Wilpen wrench series and were probably Plomb's first drop-forged products.

As the Wilpen wrenches started shipping, Plomb probably started investigating drop-forging methods and equipment, and at some point would have purchased some drop-forge hammers and hired some experienced die sinkers. For a company just experimenting with drop-forging, making relatively flat tools like open-end wrenches would have been a good starting point. Thus it would be interesting to find out whether Plomb actually sold any drop-forged open-end wrenches in the mid to late 1930s.

In any event, by 1940 Plomb was making drop-forged offset box wrenches similar to the Wilpen series, but with enough changes to indicate in-house production. And after checking the examples on this site, all of the open-end wrenches in the wartime era look to have been drop-forged. Thus it's likely that by the early 1940s the change to drop-forging was well under way.

There's even a subtle confirmation on the cover of the 1940 Plomb catalog — the 1936 catalog cover reads "Plomb Hand Forged Tools", but the 1940 cover reads "Plomb Forged Hand Tools".

Additional confirmation of the switch to drop-forging was found in a 1941 newspaper article ("KPLA" in the References section) that specifically mentions the use of drop hammers and dies.

Acquisition of Cragin Tool

In 1940 Plomb began a series of acquisitions with the purchase of the Cragin Tool Company of Chicago. The identity and history of Cragin Tool had been a long-standing mystery, but in January of 2010 Alloy Artifacts was able to identify Cragin as the successor (by name change) of the Bog Manufacturing Company, a maker of automotive specialty tools active from the 1920s onward. (See our article on Bog Manufacturing for more information.)

Fig. 2. 1941 Notice of Purchase of Menard Street Factory.

The former Bog Manufacturing facility on Menard Street in Chicago provided Plomb with substantial manufacturing capacity, and at least one Bog-designed tool is known to have been shipped as part of Plomb's Wright Field (WF) contract.

The scan in Fig. 2 shows a notice of the purchase of the Menard Street factory, as published on page 23 of the March 16, 1941 edition of the Chicago Tribune. This notice was published after the filing of the deed, somewhat after the actual sale.

The text notes the seller as George Pepperdine and the selling price as $55,000 for the factory and equipment.

After the purchase of Cragin, its president Ben Pepperdine is believed to have continued working for Plomb, and later relocated to Southern California.

Acquisition of P&C

Plomb continued its expansion with the 1941 acquisition of the P&C Hand Forged Tool Company of Milwaukie, Oregon. P&C was an interesting and innovative company in its own right, and readers can refer to our article on The P&C Hand Forged Tool Company for more information.

The Penens Mystery ... Solved!

At this point we have to pause our quick pass through Plomb history to provide a long overdue correction. The orthodox history of Plomb says that in 1942 Plomb acquired the Penens Corporation, which later became well known for its Fleet and Challenger brands of tools. This supposed acquisition has been repeated so many times that it has been accepted as true, and is even repeated on the history page of StanleyProto, the present-day successor to Plomb.

The problem is that exhaustive searches have failed to turn up any trace of a "Penens Corporation" tool company prior to the 1940s. Tool companies of the caliber acquired by Plomb don't just materialize from nowhere, so the origin of Penens has been a long running mystery.

Recently (October 2015) we were able to find definitive information showing that the Penens Corporation was simply a reorganization and renaming of the assets of Cragin Tool (aka Bog Manufacturing), rather than a separate acquisition. The key bits of information were found by a search of Google Books and were available only as snippets.

The first clue was found on page 174 of Volume 48 (1957) of Western Machinery and Steel World in a notice entitled "Pendleton Tool Elects Slining as Vice President", which announces the promotion of Henry W. Slining, a manager at Proto Tool. The notice goes on to mention that "Slining, who joined Pendleton in Los Angeles in 1936, served as vice president and plant manager of its Chicago subsidiary, Penens Tool Corp. from 1941 to 1949." (Readers new to Plomb Tool should note that Pendleton and Proto are later names for the company.)

This is a very promising lead, as it places Penens in Chicago and shows that it was already operating in 1941 as a subsidiary of Plomb. Our second clue comes from page 114 of the 1948 Volume 24 of Chain Store Age. A notice under "Penens plant moved" states "Announcement has been made that the plant of the Penens Corp. has been moved to 3900 Wesley Terrace, Schiller Park, Ill. The new plant will provide double the floor space of the old plant at Menard St., in Chicago".

If we recall that Bog Manufacturing operated at Menard Street in Chicago from the 1920s on, we can see that the "old plant at Menard St." is an obvious reference to the Bog Manufacturing factory purchased by Plomb with its 1940 acquisition of Cragin Tool. In conclusion, we see that the Penens Corporation, at least in its production facilities, was substantially the same as the Cragin Tool/Bog acquisition.

The WF Series Tools

Around 1942 Plomb landed a major tool supply contract with the U.S. Government, for which it shipped a special line of "Wright Field" WF series tools. The WF tools were an important contribution to the war effort, and Plomb was able to effectively utilize the additional manufacturing facilities it had acquired.

Acquisition of J.P. Danielson

Plomb's expansion continued in the postwar era with the 1947 acquisition of the J.P. Danielson Company, a maker of pliers and adjustable wrenches. (See our article on the J.P. Danielson Company for more information.)

Trademark Problems

In 1946 Plomb ran into an odd problem: it was sued for trademark infringement by Fayette R. Plumb, Inc., a company making hammers and other striking tools. According to an article in the December 6, 1948 issue of Time magazine, the roots of the dispute went back to 1926, when Plumb objected to an attempt to register Plomb as a trademark. Apparently the companies negotiated an agreement at the earlier time, but later actions by Plomb were deemed to violate the terms.

The Change to Proto

As a result of this trademark dispute, Plomb was required to change the brand name marked on their tools, and chose "PROTO" (from "PROfessional TOols") as the new name. In 1948 Plomb started marking tools with the "PROTO" mark (this time making sure to register the trademark), and by 1950 the Plomb name had disappeared from its tools.

Although this forced name change may have been a nuisance at the time, the company itself was largely unaffected. Plomb continued operating as the Plomb Tool Company for a number of years after 1950, making the same tool models to the same specifications as it had before, but now marked "Proto Los Angeles".

Later History

In 1957 Plomb Tool changed its name to Pendleton Tool Industries and somewhat later became a publicly-traded company in the stock market.

Pendleton continued its acquisitive ways, and in 1959 Vlchek Tool of Cleveland became part of the growing tool conglomerate.

Acquisition by Ingersoll-Rand

In 1964 Pendleton Tool Industries was acquired by Ingersoll-Rand (IR), an industrial conglomerate, and afterwards operated as the Proto Tools Division of IR.

After the acquisition Morris B. Pendleton was named to IR's board of directors.

Acquisition by Stanley

In 1984 Proto Tools was purchased from Ingersoll-Rand by The Stanley Works, a maker of hardware and carpenter's tools with operations going back to the 19th century. Our documention for this was found as a snippet in the 1984 Wall Street Journal index stating "Stanley Works agreed to purchase the Proto industrial tools unit of Ingersoll - Rand Co. for $ 40 million". (The Stanley web site also cites 1984 as the date for the Proto acquisition.)

The successor to Plomb Tools operates today as the Proto Industrial Tools Division of Stanley. Stanley went on to expand its tool operations with the purchase of the National Hand Tool Corporation in late 1986, which included the Husky and Blackhawk brands.

Further information on the company's later tools can be found in our article on the Proto Empire.

Patents

Trademarks

On February 2, 1948 Plomb Tool filed a trademark application for "PROTO" in the stylized inverted-triangle (PRVTV) form, with the first use date listed as January 23, 1948. The trademark was issued as #501,030 on July 13, 1948. This trademark was later amended replace the stylized form with "PROTO" in block letters, with the amendment effective on November 15, 1949.

On December 14, 1948 Plomb filed another application for "PROTO" in block letters, listing the first use date as January 23, 1948 (as with the first application), but with a much broader list of products covered under the mark. This second trademark was issued as #530,257 on September 5, 1950.

Manufacturing Dates

Plomb is one of several companies with a generally recognized date code system for its tools. The date code, when present, consists of a 0-9 digit giving the manufacturing year, with other markings providing the relevant decade. An in-depth description of the date codes can be found in a Plomb history web page listed in the References section, and interested readers are directed there for further reading.

The main shortcoming of the Plomb date code system was that the company applied it to only a fraction of their tool production; many tools were simply not coded with a date. However, it turns out that other markings on Plomb tools were changed fairly frequently, so that by examining these markings (and possibly other characteristics of the tool), an approximate date of manufacture can be determined in most cases.

In order to provide a framework for examining the various tool markings, we first need to divide the production years into distinct periods.

The Early Period, Up to 1933.

This period covers a relatively long interval of time, but as tool examples and catalog resources from this era are both scarce, it may be difficult to estimate dates for the earliest tools. Plomb's date code system was commenced in 1927 during this period, but prior to that, tool markings may provide a clue to the manufacturing date.

The most notable marking is the use of the name "Plomb Tool Mfg. Co." on early tools, sometimes shortened to "Plomb T.M. Co." or just "Plomb TMCO". These markings are shown in a 1924 Ducommun industrial catalog on a variety of Plomb tools. The presence of the "Plomb Tool Mfg. Co." marking (or equivalent) probably indicates manufacture in or before 1927. An example of an early "Plomb TMCO" markings can be seen on the Early Plomb TMCO Wrench; note that the Plomb name has arrowhead-like symbols on either side of the name, even on this very early example.

For Plomb tools produced from 1927 through the end of this period, the expected marking would be the Plomb name with a conventional (round) "O" as "PLOMB". The tools may also be marked with "Los Angeles", but the key to this period is the round "O".

The date code (if present) will be one of the digits {7,8,9,0,1,2,3} combined with a letter, signifying the years 1927-1933.

Fig. 3. Plomb DD16 1/2-Drive 1 Inch 12-Point Socket with Date Code "8B", 1928.

Fig. 3 shows an early Plomb DD16 1/2-drive 12-point 1 inch socket, stamped "PLOMB" and "Los Angeles" with an "8B" date code for 1928. These are the typical markings for this period.

The Los Angeles Period, 1934-1938

In 1934 Plomb started using a stylized inverted triangle for the "O" in "PLOMB", so that it looks more like "PLVMB" at first glance. The tools were still marked with "Los Angeles", so we'll use that as the name for this period. Date codes in this period will include one of the digits {4,5,6,7,8}, and sometimes "9". (Date code changeovers didn't necessarily occur at a year boundary, and sometimes took a few months to complete.)

Fig. 4. Closeup of Plomb 5348 1/2-Drive 7/8 Deep Socket with Date Code "5A", 1935.

Fig. 4 shows a closeup of a model 5348 socket with the new Plomb "PLVMB" logo and "Los Angeles" marking.

The "5A" date code indicates production in 1935.

Fig. 5. Plomb 2010 3/16x1/4 Brake Wrench, with Inset for Date Code "8B", 1938.

Fig. 5 shows a model 2010 3/16 x 1/4 brake wrench, with date code "8B" indicating 1938 production.

The finish of the wrench is polished steel with no plating.

The USA Period, 1939-1945

In 1939 Plomb dropped the "Los Angeles" marking in favor of "Made in U.S.A." on its tools, so we'll call this the USA Period. Plomb continued to use the inverted triangle "PLVMB" logo for the company name.

Plomb discontinued its date code markings after 1942, so the codes for this period will include one of the digits {9,0,1,2} representing 1939-1942.

Fig. 6. Plomb 3035 11/16x3/4 Open-End Wrench, with Inset for Date Code "1C", 1941.

Fig. 6 shows a model 3035 11/16x3/4 open-end wrench with a "1C" date code for 1941.

This wrench has a thin chrome plating (worn off in areas), as by this time Plomb was starting to use plated finishes on its tools. (Many other manufacturers had done so since the early 1930s.) However, chrome finishes disappeared during the war years due to critical material shortages.

Hot-Broached Sockets. A significant change in socket production occurred in the USA Period with the adoption of a new hot-broaching process. Where the older process left an irregular shelf of material at the bottom of the broach, the new process instead formed a distinct annular cone from the displaced material. The differences can be seen easily by a comparison of old and new sockets.

The change in socket production appears to have occurred around 1943, as dated examples from 1942 were made with the older process. Thus the socket construction can be used to distinguish earlier and later manufacture in the absence of a date code.

Fig. 7. Plomb 54xx 1/2-Drive Sockets Showing Older (Bottom Row) and Newer (Top Row) Broaching Details.

Fig. 7 shows a series of model 54xx 1/2-drive sockets paired for comparison, with the older sockets (all date-coded) in the bottom row.

The leftmost column (model 5425, 25/32) shows a 1941 socket vs. a post-1945 socket.

In the middle column (model 5426, 13/16) we see a 1942 socket vs. a 1943-1945 socket.

Finally, on the right (model 5430, 15/16) we have a 1939 socket vs. a 1943-1945 socket.

WF Series Tools. The USA Period also included the production of a separate line of Plomb tools, the WF series (for "Wright Field") produced for a large government contract. These tools are easy to identify by the "WF" prefix in their part numbers; the tools will have a "PLVMB" logo but not always a "Made in U.S.A." marking. The WF tools were produced from 1942 through 1945.

Another marking peculiar to the USA Period was the notation "War Finish" (not to be confused with "WF") to indicate that some aspect of the tool's material or workmanship had been compromised.

Fig. 8. Plomb 8160 3/8 x 7/16 Box-End Offset Wrench, with Inset Showing "War Finish", ca. 1944-45.

Fig. 8 shows an example of a "War Finish" notation on a Plomb 8160 box-end wrench.

If this notation indicated a shortage of materials (or labor), it might be thought to have been more prevalent during the last years of the war, and so suggests a manufacture date of 1944-1945.

However, the example in Fig. 9 below appears to be from 1942, so some production problems may have occurred even earlier.

Fig. 9. Plomb 1/2-Drive 5428 7/8 Socket, with Inset Showing "War Finish", ca. 1942.

Fig. 9 shows another example of the "War Finish" marking, this time on a 1/2-drive model 5428 7/8 socket.

The markings are "Made in U.S.A." with a "CC" code next to "War Finish", as shown in the inset.

The finish is plain steel.

The construction of this socket is cold-broached, which would suggest manufacture in or before 1942.

One other oddity in markings, apparently peculiar to the USA Period, was brought to our attention by a sharp-eyed reader. The PLVMB logo used by Plomb is generally flanked by arrowheads on either end, both pointing down to match the inverted "V". (Some would say these are really plumb bobs, added to irritate the Plumb tool company.) But on some tools made during the USA Period, one of the arrowheads has been marked pointing up instead of down.

There are a number of examples of this sprinkled throughout this article; see for instance the 5285 Breaker, 4785 Breaker, WF-22 Breaker, WF-37 Breaker, or WF-83 Wrench. These particular cases have the righthand arrowhead pointing up, but other examples have been found with an Up/Down pattern. (No Up/Up examples have been spotted so far though.)

Based on an unscientific sample, this marking oddity is uncommon but not actually rare, and appears to occur more frequently in the WF-series tools. The meaning of these markings, if any, is not known at this point; perhaps it was just a setup error on the marking machine.

The Pebble Period, 1945-1948

After the end of the war Plomb changed many of its tools to include a "pebbled" background on the flat forged areas. Tools continued to be marked with "Made in U.S.A." or the variant "MFD. U.S.A.", sometimes interchangeably on the same model. But the markings were now forged into the shank against the pebbled background, instead of being stamped.

Fig. 10. Plomb 1218 Combination Wrenches with "Made in U.S.A." Variants, ca. 1945-1948.

Fig. 10 shows two Plomb 1218 9/16 combination wrenches in the pebble style, illustrating variations in the markings. The forged-in markings show "Made in U.S.A." on the bottom wrench and "MFD. U.S.A." on the top example.

Not all of the tool production was made in the new pebbled style; in particular, sockets were not amenable to this kind of forging.

In addition to the pebbled backgrounds, Plomb provided chromium plated finishes for most of its tools during this period.

The Proto Period, 1948-1949

On January 23, 1948 (according to the trademark records, at least), Plomb began marking its tools with the new "PROTO" trademark, but also included a "PLOMB TOOL CO." mark. (Inverted triangles were used for all of the "O"s.) At the same time, the pebbled background was reduced to just a box surrounding the size markings, so these are sometimes referred to as the "pebbled size field" tools. Apart from the sizes, the other markings went back to being stamped as they had been prior to the "Pebble" era.

Fig. 11. Wrenches Marked "Proto Plomb Tool Co." with Pebbled Size Fields, ca. 1948-1949.

Fig. 11 shows two examples of double-open wrenches with this style of marking.

Unfortunately for Plomb, the inclusion of the "PLOMB TOOL CO." mark was considered a breach of the court agreement that settled their original trademark infringement lawsuit. Plomb ended up paying a considerable fine for this miscue, and in the final settlement was allowed to use the "Plomb" name on tools only through the end of 1949 (actually a few months into 1950). After this the Plomb name disappeared from the tools, but the company continued to operate as the Plomb Tool Company for a number of years.

Summary of Production Periods

With an understanding of these production periods, you should be able to take most Plomb-marked tools and classify them into one of the periods. This will provide at least an approximate age for the tool, even when no date code is marked, and from there further refinements may be possible based on production details.

A few caveats apply, however. Plomb is known to have produced special-order tools for large customers, and these may not follow the standard marking rules. In addition, Plomb (like most major manufacturers) may have outsourced some of their production to smaller specialty companies, and these tools again may not follow the normal markings. For example, if the contract manufacturer didn't have the special marking die for the PLVMB logo, their production might have been marked with a round-O Plomb when the inverted triangle was expected.

That completes our brief introduction to the Plomb Tool Company.

References and Resources

The photographs and observations of specific tools are from items in the Alloy Artifacts collection.

The Proto Tools (successor to Plomb) website has expanded their historical information in conjunction with the 100th anniversary (1907-2007) of Plomb and Proto. A brief history of Proto can be found on the company's Proto History [External Link] web page. [Sorry, dead link 😢] It appears that Proto Tools no longer provides a summary of the company's history.

PTP. The archive of an excellent website created by an avid Plomb tool collector can be found at The History of PLOMB Tools [External Link]. The interested reader may want to check there for additional information regarding Plomb. (This site is referred to as the "PTP" for "Plomb Tools Page" in the text here.)

KPLA. Backgound information on Plomb history was found in an article on Morris Pendleton entitled "Key Posts in L.A.", published on page 13 of the September 6, 1941 edition of the Los Angeles Times.

Information regarding the Plumb trademark lawsuit is available in a brief article entitled "Plumb v. Plomb" in the December 6, 1948 issue of Time magazine.

An obituary for Morris B. Pendleton [External Link] in the February 24, 1985 issue of the Los Angeles Times provides information on the life and activities of Plomb's long-serving president.

Plomb Employee Newsletters

Plomb published an employee newsletter during the 1930s and 1940s, which while mostly filled with mundane matters of daily life at Plomb occasionally provide a gem of information. For example, had a copy of a newsletter from 1933 announcing a new "combination wrench" not been preserved, Plomb probably would not have been recognized as the originator of this popular style.

Recently a trove of Plomb "Anvil Chorus" newsletters from 1944-1945 have been digitized and posted at the International Tool Catalog Library, and interested readers can browse the Anvil Chorus Newsletters [External Link] at the ITCL web site.

Catalog Coverage

Product information was obtained from a number of Plomb catalogs, as summarized in the table below.

Industrial Distributors

Plomb tools were available from some industrial distributors, and the catalogs from these companies provide a valuable supplement to the Plomb catalogs.

• Ducommun "F" 1924. The 1924 catalog "F" from the Ducommun Corporation lists Plomb tools including open-end wrenches, chisels, punches, and bearing scrapers. The illustrations show the early "Plomb Tool Mfg. Co." marking.

• Ducommun "G" 1926. The 1926 catalog "G" from the Ducommun Corporation lists only a few Plomb tools, consisting of chisels, oil groovers, and a cotter pin puller. The illustration for a Plomb No. 508 chisel set on page 269 shows a tool roll with the "Plomb Tool Mfg. Co." marking.

• C.W. Marwedel 1929. The 1929 catalog No. 12 from the C.W. Marwedel Company lists a variety of Plomb tools scattered throughout the catalog. The listings include Plomb water pump wrenches in models from W20 (1-1/4) to W28 (1-3/4) on page 78, chisels on pages 166-167, several types of punches on page 171, and a model HB3 brass hammer on page 192.

• Waterhouse-Lester-Scovel 1930. The Waterhouse-Lester-Scovel catalog No. 21 from around 1930 offers an extensive selection of Plomb tools. The listings include Plomb body and fender tools on pages 606-607, pliers on page 610, screwdrivers on page 611, chisels and punches on pages 618-620, sockets and drive tools on pages 632-637, open-end wrenches on pages 638-639, and specialty tools on pages 640-642. The listings even include the rare 7/8-male drive "Big Bertha" socket tools on page 637.

  Other listings include Plomb gear pullers on page 60, stud pullers on page 61, Ford wheel pullers on page 61, and knock-off wheel pullers on page 61.

  This catalog is undated and was published without copyright, but the date can be estimated as 1929-1930 by the contents.

Advertisements

Plomb placed advertisements in a number of trade magazines and other periodicals, and these ads provide an interesting snapshot of the tools available at various times.

• The December 1928 issue of Popular Science Monthly included an ad for a Plomb Hand-Forged Screwdriver on page 90 at the upper left. The text notes the use of tungsten steel, and the ad also offers a Plomb hand-forged keyring screwdriver for just 12 cents in stamps. Another interesting detail to note is that the Plomb name at the top is written in the PLVMB form with an inverted triangle.

• The March 1929 issue of Popular Science Monthly included an ad for Plomb Sockets on page 100 at the upper left. The ad notes the use of molybdenum steel in the sockets, and shows a number of the drive tools available at the time.

• The June 1929 issue of Popular Science Monthly shows an ad for Plomb Punch and Chisel Sets on page 104 at the upper left.

Early Tools

Although Plomb began operations in 1907, the surviving record of their production doesn't extend much earlier than the 1920s. The company's earlier production included striking tools such as chisels, which tend to be consumed during use and eventually discarded. In addition, it's not known whether the earliest tools were even marked, making later identification nearly impossible.

From the 1920s onward we have some catalog references to indicate the tool styles and markings used by Plomb.

In this section we'll look at examples of Plomb's early production, covering approximately the early 1920s to early 1930s. To better define what we mean by "early", the tools in this section will be identified by at least one of the attributes in the following list.

• "Plomb Tool Mfg. Co." Marking.
• PLOMB Name with Round "O". (Except for obvious contract production.)
• Early Model Number.
• Construction or Style Not Known from Catalogs.

Early Open-End Wrenches

Rare Early [1516] 15/16x1 Open-End Wrench

We'll begin this section with two very early examples of open-end wrenches with 22-1/2 degree offsets, made before the offsets were standardized at 15 degrees.

Fig. 12. Early Plomb 1516 15/16x1 Open-End Wrench, with Insets for Side View and Marking Detail, ca. Early to Mid 1920s.

Fig. 12 shows an early Plomb [1516] 15/16x1 open-end wrench, stamped "PLOMB Tool Co." (using a round "O") and "L.A. Cal." on the shank.

The overall length is 9.3 inches, and the finish is plain steel.

The top inset shows the extremely thick construction of this wrench, measured at approximately 0.43 for the shank and 0.47 for the openings.

Rare Early 1214 3/4x7/8 Open-End Wrench

Fig. 13. Early Plomb 1214 3/4x7/8 Open-End Wrench, ca. 1921-1927.

Fig. 13 shows an early Plomb model 1214 3/4x7/8 open-end wrench, stamped "PLOMB TMCO" (using a round "O") and "Los Angeles" on the shank.

The overall length is 7.8 inches, and the finish is plain steel.

The "PLOMB TMCO" mark is a shortened form for "Plomb Tool Mfg. Co.", the name used on Plomb tools up through (approximately) the late 1920s.

The wrench is forged from heavy steel plate with stamped openings, the method Plomb used for open-end wrenches up until the late 1920s or very early 1930s.

Wrenches of this style are shown in a 1924 catalog from the Ducommun Corp., a west-coast industrial supplier, and the 3/4x7/8 size is included among the 8 models listed. The catalog illustration shows the wrenches with "Plomb Tool Mfg. Co." markings, but no model numbers are given.

An automotive supplier listing of Plomb tools from around 1930 also shows this type of wrench in an Oxxyy series, where "xx" and "yy" were the opening sizes in 16ths. However, the particular size for this wrench wasn't among the listed O-series models; the standard wrenches went from O1112 (11/16x3/4) to O1314 (13/16x7/8).

As a side note, the earliest 15-degree offset open-end wrenches were first given model numbers in an X-series, with sizing as for the O-series. The model numbers were later reworked into the 30xx numbers seen in the examples below.

A uncommon tool such as this deserves a story as to how it came to reside in our virtual museum. This wrench was a fortuitous find on the $0.25 bargain table of a used tool emporium, discovered while searching through a pile of rusty tools. The odd-looking wrench could have been easily overlooked except for the barely-visible "MB" of "PLOMB", and a quick wire-brushing confirmed the identification as an early Plomb wrench.

Rare Early O910 9/16x5/8 Open-End Wrenches

The next two figures show additional examples of early wrenches with 22-1/2 degree offsets, but now with an O-series model number.

Fig. 14. Plomb Early O910 9/16x5/8 Open-End Wrench, 1929.

Fig. 14 shows an early Plomb O910 9/16x5/8 open-end wrench, stamped with the PLOMB (round-"O") logo and "Los Angeles", and with a "9C" date code for 1929.

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

Fig. 15. Plomb Early O910 9/16x5/8 Open-End Wrench, 1930.

Fig. 15 shows another early Plomb O910 9/16x5/8 open-end wrench, stamped with the PLOMB (round-"O") logo and "Los Angeles", and with a "30A" date code for 1930.

The overall length is 6.2 inches, and the finish is plain steel.

Rare Early "KI" 5/8 Stubby Single-Open Wrench

This next figure shows an unusual stubby single-open wrench, the first one of this type in our collection.

Fig. 16. Plomb Early "KI" 5/8 Stubby Single-Open Wrench, ca. 1920s.

Fig. 16 shows an early Plomb "KI" 5/8 stubby single-open wrench, stamped with the model, size, and PLOMB (round-"O") logo.

The overall length is 3.1 inches, and the finish is plain steel.

Currently we don't have a catalog reference for this wrench and so are unsure of the application. The simplified markings -- without even the usual "plumb bobs" -- suggest an early production date.

Tappet Wrenches

Tappet wrenches are another important subset of open-end wrenches, typically intended for adjusting the lock nuts on valve tappets. These wrenches feature thin construction with longer handles.

We'll begin this section with several early Plomb U-series tappet wrenches, all dating from the late 1920s.

U910 Early 9/16x5/8 Tappet Wrenches

The next two figures show similar examples of very early U910 tappet wrenches.

Fig. 17. Plomb U910 9/16x5/8 Tappet Wrench, 1927.

Fig. 17 shows an early Plomb U910 9/16x5/8 tappet wrench, stamped "PLOMB Los Angeles" with a "7A" date code for 1927.

The overall length is 7.7 inches, and the finish is polished steel.

Fig. 18. Plomb U910 9/16x5/8 Tappet Wrench, 1927.

Fig. 18 shows another early Plomb U910 9/16x5/8 tappet wrench, stamped "PLOMB Los Angeles" with a "7B" date code for 1927.

The overall length is 7.8 inches, and the finish is polished steel.

U1112 Early 11/16x3/4 Tappet Wrench

Fig. 19. Plomb U1112 11/16x3/4 Tappet Wrench, 1927.

Fig. 19 shows another early example, a Plomb U1112 11/16x3/4 tappet wrench, stamped "PLOMB Los Angeles" with a "7A" date code for 1927.

The overall length is 8.5 inches, and the finish is polished steel.

V89 Early 1/2x9/16 Tappet Wrench

Fig. 20. Plomb V89 1/2x9/16 Tappet Wrench, 1930.

Fig. 20 shows an early Plomb V89 1/2x9/16 tappet wrench, stamped "PLOMB Los Angeles" with a "0B" date code for 1930.

The overall length is 9.0 inches, and the finish is nickel plating with polished faces.

V910 Early 9/16x5/8 Tappet Wrench

Fig. 21. Plomb V910 9/16x5/8 Tappet Wrench, 1931.

Fig. 21 shows an early Plomb V910 9/16x5/8 tappet wrench, stamped "PLOMB Los Angeles" with a "C1" date code for 1931.

The overall length is 8.9 inches, and the finish is nickel plating with polished faces.

V1314 Early 13/16x7/8 Tappet Wrench

Fig. 22. Plomb V1314 13/16x7/8 Tappet Wrench, 1929.

Fig. 22 shows an early Plomb V1314 13/16x7/8 tappet wrench, stamped "PLOMB Los Angeles" with a "9A" date code for 1929.

The overall length is 9.0 inches, and the finish is nickel plating with polished faces.

12-Point Box-End Wrenches

By 1926 Plomb was offering an A-series of single-ended 12-point box wrenches, making it one of the earliest (along with P&C) companies to offer such tools. These wrenches were an important new class of tools made possible by alloy steel.

By 1928 Plomb had added an AD-series of double-ended offset 12-point box wrenches, available in six sizes from 7/16x1/2 up to 15/16x1 inch.

Fig. 23A. 1928 Catalog Listing for Plomb Box-End Wrenches.

The scan in Fig. 23A shows a listing for single-ended and double-ended 12-point box wrenches, as published on page 6 of Plomb catalog No. 8 from 1928.

The text for the AD-series notes that the wrenches were hand forged from molybdenum steel.

The A-series single-ended wrenches (shown at the left in the illustration) had been available since 1926.

We'll begin this section with several examples of early wrenches, all produced before the modern model number system had been established. In the earlier system, model numbers for box-end wrenches were based on opening sizes, but with the sizes measured in 16ths.

AD78 7/16x1/2 Box-End Wrench

Fig. 23. Plomb AD78 7/16x1/2 Box-End Wrench, with Insets for Side View and Back Side Detail, 1928.

Fig. 23 shows an early Plomb AD78 7/16x1/2 box-end wrench, stamped with the PLOMB (round-O) logo and "Los Angeles", and with a date code of "8B" for 1928.

The overall length is 6.1 inches, and the finish is plain steel.

AD910 9/16x5/8 Box-End Wrench

Fig. 24. Plomb AD910 91/16x5/8 Box-End Wrench, with Inset for Side View, 1929.

Fig. 24 shows an early Plomb AD910 9/16x5/8 box-end wrench, stamped with the PLOMB (round-O) logo and "Los Angeles", and with a date code of "9C" for 1929.

The overall length is 8.1 inches, and the finish is polished steel.

AD1112 11/16x3/4 Box-End Wrench

Fig. 25. Plomb AD1112 11/16x3/4 Box-End Wrench, with Inset for Detail, 1930.

Fig. 25 shows an early Plomb AD1112 11/16x3/4 box-end wrench, marked with the PLOMB (round-O) logo and "Los Angeles", and with a date code of "0C" for 1930.

The overall length is 10.5 inches, and the finish is polished steel.

Male-Drive Sockets

Plomb's production of standard square-drive socket tools began around 1927, but prior to this time Plomb experimented with various non-standard drive formats, including male-drive sockets in both hex and square formats. Most of these were discontinued once the standard square drive tools became available, but sockets in the largest drive size, the "Big Bertha" 7/8-drive tools, continued to be made with male-drive sockets until at least 1933.

Tools of this early vintage are hard to find and generally poorly understood, due to a lack of catalog documentation and the scarcity of examples. However, we do have a few examples to present, and hope to acquire more in the future.

Early 9/16 Speeder Socket Wrench

Fig. 26. Plomb 9/16 Speeder Socket Wrench, with Insets for Marking Detail and Broaching, ca. 1924-1927.

Fig. 26 shows an early Plomb 9/16 speeder socket wrench, which served both as a 9/16 socket wrench and as the drive tool for a set of 9/16 male hex drive sockets. The speeder is marked "Plomb Tool Mfg. Co." near the socket end, as shown in the left inset.

The overall length is 17.6 inches, and the finish is black oxide.

The speeder wrench was acquired with three matching 9/16 male hex drive sockets, as shown in the next figure.

Early 9/16-Male Hex Drive Sockets

Fig. 27. Plomb 9/16 Male Hex Drive Sockets, with Insets for Marking Detail, ca. 1924-1927.

Fig. 27 shows the set of 9/16 male hex drive sockets acquired with the speeder, all marked "Plomb" with plumb-bob symbols at each end. (The hole in the marking for the middle socket is the back end of the friction ball recess.) The sizes are, from the left, 7/16, 1/2, and 5/8.

The 9/16 drive tang of each socket is equipped with a friction ball to secure the socket in the speeder wrench.

The three socket sizes together with the 9/16 speeder wrench covered the common hex sizes from 7/16 to 5/8, making this set convenient for many common service jobs.

Sockets with hexagonal male drive tangs are something of a rarity in the tool industry, with the only other examples being the Billmont "Master Wrench" Sets of the early 1920s and another obscure maker called the Eastern Machine Screw Company, also from the early 1920s.

For the Billmont sockets the hexagonal drive tang was actually machined from bar steel, a time-consuming operation that may have contributed to the company's early demise. In Plomb's case the sockets were probably made by starting with 9/16 hexagonal bar steel and upsetting it to form the socket, though other methods would be possible for a hot-forging specialist.

Early S178 1/2 Hex Brace Socket Wrench

This next figure shows a similar Plomb brace socket wrench.

Fig. 28. Plomb S178 1/2 Hex Brace Socket Wrench, with Insets for Construction and Marking Detail, 1927.

Fig. 28 shows an early Plomb S178 1/2 hex brace socket wrench, stamped with the PLOMB (round-O) logo and "Los Angeles", and with a "7A" date code for 1927. (The date code is split by the "Los Angeles" marking, an oddity frequently seen on early Plomb tools.)

The overall length is 16.8 inches, and the finish is plain steel.

This brace socket wrench is very similar to the Plomb 9/16 Speeder Wrench shown in an earlier figure.

Early 9/16-Male Square Drive 13/16 Hex Socket

In addition to the 9/16 male hex drive sockets, Plomb also produced sockets with 9/16 male square drive tangs. The next two figures show examples of these early sockets.

Fig. 29. Plomb Early 9/16 Male Drive 13/16 Hex Socket, with Inset for Broaching, ca. 1924-1927.

Fig. 29 shows a Plomb 9/16 male square drive 13/16 hex socket, stamped "Plomb Tool Co." and "L.A. CAL." on the drive tang. The drive tang is also stamped with the "13/16" fractional size (not shown).

The 9/16 square drive tang is equipped with a friction ball to secure the socket in a drive tool.

Early 9/16-Male Square Drive 1 Inch Hex Socket

Fig. 30A. Plomb Early 9/16 Male Drive 1 Inch Hex Socket, with Inset for Broaching, ca. 1924-1927.

Fig. 30A shows a Plomb 9/16 male square drive 1 inch hex socket, stamped "Plomb Tool Co." and "L.A. CA" on the drive tang.

The 9/16 square drive tang is equipped with a friction ball to secure the socket in a drive tool.

This socket was not marked with the size, although the drive tang has a stamped "9" on the side with the detent ball. The size was measured at 1.03 inches, slightly oversize for a 1 inch nominal socket.

7/8-Male Drive Socket Tools

Prior to 1935 Plomb's largest socket tools were based on 7/8-inch male drive sockets. These tools were amusingly called the "Big Bertha" socket set, and although we don't have any examples to show, this next figure offers an illustration of the tools from an early catalog.

The humorous name "Big Bertha" used here originally referred to a large gun used by the German army in World War I, but later appears to have become part of the popular culture of the 1920s.

Fig. 30B. 1930 Catalog Illustration of Big Bertha Socket Set.

The scan in Fig. 30B shows a catalog illustration of Plomb's "Big Bertha" 7/8-drive socket set, published on page 637 of the Waterhouse-Lester-Scovel catalog No. 21 from around 1930.

The catalog listing describes the Zxx series of sockets with 7/8 square drive shanks, in sizes from 15/16 through 2 inches, together with the ZR14 ratchet, ZH breaker bar, and ZE extension.

Waterhouse-Lester-Scovel offered an extensive selection of Plomb tools, showing that Plomb tools were available through the industrial distributors of the time.

1/2-Drive Tools

Based on catalog information and known examples, Plomb's production of standard 1/2 square-drive socket tools began in 1927.

DR8 1/2-Drive Ratchet

Fig. 31. Plomb DR8 1/2-Drive Ratchet, with Insets for Side View and Marking Detail, Late 1920s.

Fig. 31 shows an early 1/2-drive Plomb DR8 ratchet, stamped "Los Angeles" with the PLOMB (round-O) logo.

The overall length is 10.5 inches, and the finish is polished steel.

The ratchet mechanism has a 32-tooth drive gear, a relatively fine pitch for an early ratchet. The female drive gear was intended for use with a DA8 push-through drive plug.

This particular tool is not marked with a date code, suggesting that it may have been made before the general adoption of the date code system.

The DR8 ratchet was one of the tools included in the Plomb DD120 socket set, and the ratchet can be seen in a March 1929 advertisement for Plomb Socket Sets.

DTH 1/2-Drive Flex-Head (Hinge) Handle

Fig. 32. Plomb DTH 1/2-Drive Flex-Head Handle, with Insets for Detail, 1931.

Fig. 32 shows an early 1/2-drive Plomb DTH flex-head handle, called a "hinge handle" in the catalogs. The tool is marked "Los Angeles" with the PLOMB (round-O) logo and a "1D" date code, plus the patent notice "Patent 1380643".

The overall length is 18.5 inches, and the finish is polished steel.

The date code indicates production in 1931, and the "DTH" model similarly indicates early production. This flex handle would later be given model number 5468, as we'll see in a later figure.

This tool is covered under patent #1,380,643, issued in 1921 to S. Eagle.

Early DD16 1/2-Drive 1 Inch Sockets

Plomb's earliest 1/2-drive sockets were given model numbers with a "DD" prefix, with sizes in 16ths instead of 32nds. These sockets were produced beginning in 1927.

Fig. 33. Early Plomb DD16 1/2-Drive 1 Inch Socket, with Insets for Broaching and Marking Detail, 1927.

Fig. 33 shows a very early 1/2-drive Plomb DD16 1 inch socket, marked with the PLOMB (round-O) logo and "Los Angeles", and with an "7A" date code for 1927.

The finish is plain steel, with extensive pitting due to rust.

With its date code for 1927, this socket is currently our earliest example of a Plomb standard 1/2-drive socket.

Fig. 34. Early Plomb DD16 1 Inch Socket, 1928.

Fig. 34 shows another early 1/2-drive Plomb DD16 1 inch socket, marked with the PLOMB (round-O) logo and "Los Angeles", and with an "8B" date code for 1928.

The finish is plain steel.

Early DD15-1/2 "Rope-Banded" 1/2-Drive 31/32 Socket

The next figure shows an early example of a socket with a rope-like knurled band, a decorative style used by Plomb in the late 1920s and early 1930s.

Fig. 35A. Early Plomb DD15-1/2 "Rope-Banded" 1/2-Drive 31/32 Socket, with Insets for Broaching and Marking Detail, 1929.

Fig. 35A shows an early 1/2-drive Plomb DD15-1/2 31/32 socket in the "Rope-Banded" style, marked with the PLOMB (round-O) logo and "Los Angeles", and with a "9B" date code for 1929.

The finish is plain steel.

The right inset shows the interior of the socket, illustrating the cold-broached construction. The chips from the broaching operation have been flattened against a shelf, and the walls show chatter marks from the metal shearing.

This socket has a band of slanted knurling around the center, a style sometimes referred to as "Rope-Banded" due to the resemblance to a braided rope. The knurled band is primarily cosmetic and appears on a subset of Plomb's early socket production.

Based on information from other collectors, rope-banded sockets are known to have been made from at least 1929 through 1933. Interestingly though, this production overlaps with the production of non-banded sockets, raising the question as to why the different styles were being made.

3/4-Drive Tools

Based on catalog information and known examples, by 1929 Plomb was producing 3/4-drive socket tools.

DDX25 Early 3/4-Drive 1-9/16 Socket

Fig. 35B. Plomb DDX25 3/4-Drive 1-9/16 Socket, with Insets for Broaching and Marking Detail, 1929.

Fig. 35B shows an early 3/4-drive Plomb DDX25 1-9/16 socket, stamped "Los Angeles" with the PLOMB (Round-O) logo and a "9A" date code for 1929.

The finish is polished steel, and the socket is decorated with five shallow grooves, a design feature used by Plomb for a number of years.

This socket is an early example of Plomb's "deep" format, with a height of 2.9 inches to allow clearance for long bolts. Later production increased the height of the deep sockets to 3.5 inches, but this example shows that the deep format had an early beginning.

The lower right inset shows the broached interior of the sockets. Chatter marks from the cold broaching operation are present on both the square drive opening as well as the service opening.

With its date code for 1929, this socket is currently our earliest example of a 3/4-drive Plomb socket.

Other Early Tools

Plomb made a wide variety of tools beyond what is on display here, including body and fender hammers, dollies, and spoons, as well as many styles of chisels and punches. In the absence of physical examples, we will show a few early catalog listings to give the reader some idea of the range of tools available.

Catalog Listing of Chisel Set

Fig. 36A. 1926 Catalog Listing of Plomb Chisel Set.

The scan in Fig. 36A shows a Plomb chisel set in a tool roll, as published on page 269 of the 1926 catalog "G" from the Ducommun Corporation.

Catalog Listing of Body and Fender Tools

Fig. 36B. 1930 Catalog Listing of Plomb Body and Fender Tools.

The scan in Fig. 36B shows a catalog listing of Plomb body-work hammers, as published on page 606 of the Waterhouse-Lester-Scovel catalog No. 21 from around 1930. (The catalog is undated and was published without copyright, but the date can be estimated as 1929-1930 by the contents.)

The page shows a selection of hammers variously described as bumping, dinging, or fender hammers, as well as several fender dollies.