Allen Manufacturing Company

Table of Contents

Introduction

The Allen Manufacturing Company was the originator of socket-head set screws and is best known for its eponymous "Allen wrench", the familiar ell-shaped hexagonal wrenches used with set screws.

Company History

The Allen Manufacturing Company was founded by William G. Allen in 1910 in Hartford, Connecticut. The company's earliest product was a safety set screw using an internal hexagonal socket, along with a hexagonal Ell-handle to drive the screws.

At that time conventional set screws for machine tool accessories used a square head that projected well above the tooling, leading to the possibility of a worker's clothing being snagged by the screw head, resulting in a gruesome accident. Allen's set screws could be tightened into a recess so that there was no projecting head, and Allen promoted its products as a safer alternative to square head set screws.

Fig. 1. 1910 Advertisement for Allen Mfg. Safety Set Screws. [External Link]

Allen's safety screws were based on patent 960,244, filed by W.G. Allen in 1909 and issued on June 7, 1910. The patent describes a method of cold-forming a screw head around a hexagonal die.

The advertisement in Fig. 1 was published in the 1910 Annual Convention of the International Association of Factory Inspectors and illustrates the new Allen safety set screw.

The text notes the patented process used to create the screws.

Fig. 2. 1914 Advertisement for Allen Mfg. Safety Set Screws. [External Link]

As Allen found success with its new safety set screws, it faced competition when other manufacturers started making set screws with conventional broached hexagonal openings.

Fig. 2 shows an ad inviting customers to compare broached set screws with Allen's patented screws, as published on page 101 of the December 31, 1914 issue of American Machinist.

The text notes that the Allen screws provide a hexagonal socket to the full depth of the hole, but broached screws use only part of the depth due to the accumulated chips.

Fig. 3A. 1919 Advertisement for Allen Mfg. Safety Set Screws. [External Link]

Fig. 3A shows a later ad for the company's safety set screws, as published on page 112 of the February 27, 1919 issue of Automotive Industries.

The top of the illustration shows a diamond logo with "The Allen" in the center, a design claimed as a trademark in some publications. We haven't yet located the registration number.

Fig. 3B. 1921 Notice for Allen Mfg. Rim Wrench. [External Link]

Fig. 3B shows a notice for an Allen rim wrench, as published on page 36 of the July 15, 1921 issue of Southern Hardware and Implement Journal.

The rim wrench was apparently Allen's first attempt to use its cold-forming process for automotive tools, and was followed shortly by a line of socket wrench products.

The Bay State Connection

By the early 1920s Allen Manufacturing was well established as the maker of safety set screws and related hardware. At that time the market for automotive socket sets was booming, and heavy-wall turned and broached sockets were rapidly replacing the older pressed steel sockets. Realizing that its Allen process could be used to create interchangeable sockets as well as set screws, Allen Manufacturing decided to enter the market for automotive socket wrench sets.

The approach they took was to acquire the Bay State Pump Company, a Boston-based company which had just recently switched from making pressed-steel socket sets to using machined and broached sockets with hexagonal Ell-handles. We haven't found details of the acquisition, but by 1922 Allen was producing socket sets using the "Bay State" name, indicating that they must have acquired Bay State Pump.

The "Bay State" brand had been used by a succession of companies in the Boston area, beginning with Bay State Tool in 1906, then Tudor Manufacturing, and finally the Bay State Pump Company.

Fig. 4. 1922 Notice for Allen Mfg. Bay State No. 21-1 Set. [External Link]

The composite scan in Fig. 4 shows a notice for the "Bay State No. 21-1 Set", as published on page 43 of the March 9, 1922 issue of Motor Age. (The image was edited to combine the text and illustration.)

The text describes the set and notes the maker as Allen Manufacturing of Hartford. This is currently our earliest reference to the Allen "Bay State" sets.

Fig. 5. 1922 Ad for Allen Mfg. Bay State Socket Set. [External Link]

The scan in Fig. 5 shows an advertisement for Bay State socket wrench sets, as published on page 56 of the April 6, 1922 issue of Motor Age.

Note that the ad is actually soliciting sales agents or distributors for the socket sets. This suggests that Allen may have had difficulties getting its new socket set products into distribution channels, possibly because the company was known as a hardware manufacturer rather than a tool maker.

The text describes the No. 21-1 set, which consisted of a ratchet head, a handle, an extension, a drive plug, a universal, and eight sockets ranging from 7/16 to 25/32.

The most interesting detail in the description is that the sockets were made by the Allen process, a method of cold forming whereby the steel socket blank is forced under great pressure to flow around a mandrel.

This is the dominant process for making sockets today, but it was very novel in the 1920s, and Allen is the only company known to have used this technique at that time. Using the Allen process to make interchangeable sockets was a natural extension of their 1910 patent 960,244, and the sockets thus produced would have been covered by the patent.

A similar ad was published on page 136 of the April, 1922 issue of Popular Mechanics, and a Spanish-language version was published on page 40 of the May, 1922 issue of El Automóvil Americano.

Fig. 6. 1922 Notice for Allen Mfg. Bay State No. 19 Socket Set. [External Link]

Fig. 6 shows a slightly later notice illustrating an Allen "Bay State" No. 19 socket set, as published on page 756 of the May 18, 1922 issue of American Machinist.

Note that the illustration in this notice shows a simple label on the front of the box, but no label on the inside lid.

By comparison, the illustration of the No. 19 set in the Allen catalog (see Fig. 7 below) shows a distinctive label placed in the center of the inside lid, with "Bay State" along the diagonal of the label. In addition, the screwdriver promised in this notice did not make it into the illustration or description in the catalog.

These differences suggest that the notice in Fig. 6 was prepared from an early prototype of the set.

A search for public references to the Allen "Bay State" sets found a flurry of notices and advertisements in 1922, but nothing after that except for two product directory listings from 1924 and 1925. The absence of any product advertisements in 1923 or later suggests that Allen quickly realized that the sets were not going to be commercially successful. We think it's likely that the sets were discontinued after 1925.

Later Operations

In 1956 Allen Manufacturing became a subsidiary of Chicago Pneumatic, and in 1986 was acquired by the Danaher Corporation, a conglomerate with extensive operations in hand tool manufacturing.

Allen Manufacturing continues today (or at least its brand does) as part of the Apex Tools Group.

Patents

Trademarks

References and Resources

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

Catalog Resources

We are fortunate to have an early catalog for Allen Manufacturing, courtesy of the International Tool Catalog Library. The catalog was published undated and without copyright, but has a handwritten 1925 date from a former owner. However, our analysis provides evidence that the catalog was actually published in the spring of 1922, as Allen prepared to launch its new socket wrench sets.

Our estimate of the publication date is based on a progression of illustrations of one of the socket sets, as well as the obvious observation that the primary reason to publish a new catalog is the need to announce new products. The catalog devotes 10 of its 32 pages to Allen's new "Bay State" socket wrench sets, which were very different from its existing line of hardware products. The earliest known public references to these sets are from the spring of 1922.

Now consider the illustrations in Fig. 6, Fig. 7, and Fig. 8 (our photograph), which form a progression based on successive refinement of detail. The illustration in Fig. 6 was published in May of 1922 in a notice stating that the socket sets had been placed on the market. If we assume a lead time of a month or two for the notice, this implies that the catalog illustration in Fig. 7 would have been prepared in April or May of 1922.

These considerations provide strong evidence that the catalog was published in the spring of 1922.

Selected Tools

Allen Manufacturing is best known for their Ell-handle "Allen" wrenches, and it's a safe bet that virtually 100 percent of our readers have used an Allen wrench, whether for repairing machinery, assembling furniture, or securing bathroom fixtures. Since these tools are so familiar, we won't bother displaying them here.

Most of Allen's other products would be properly classified as hardware, and as such are outside of the primary interest of this site. This leaves us in the unusual position of presenting a company based on its rarest and least familiar products, the Allen "Bay State" socket sets of the early 1920s. However, we believe that these socket sets are historically important as the first examples of cold-forming technology applied to socket production, and we are very pleased to be able to present these sets.

Allen Mfg. 7/16-Hex Drive "Bay State" No. 19 Socket Set

Fig. 7. 1922 Catalog Listing for Allen "Bay State" No. 19 Set.

The scan in Fig. 7 shows a listing for the Allen Mfg. "Bay State" No. 19 socket set, as published on page 26 of the Allen catalog from around 1922.

The illustration shows a label in the center of the inside lid, with "Bay State Socket Wrench Set" along the diagonal.

If we compare this illustration with the actual set in Fig. 8 below, two minor changes are apparent. The first is that the label has been moved to the upper left corner of the lid, to make room for a small piece of wood used to secure the drive tools in place.

The second change is that a wooden organizer has been added to hold the sockets in place. These changes indicate that the catalog illustration was prepared from a prototype shortly before the set was finalized for production.

Fig. 8. Allen Mfg. "Bay State" No. 19 Socket Set, ca. 1922 to Mid 1920s.

Fig. 8 shows a 7/16-hex drive Allen "Bay State" No. 19 socket set, consisting of a ratchet head, a handle bar, an Ell handle, a two-piece universal, a long extension, a drive plug, nine hexagon sockets, and three square sockets. (The drive plug was accidentally omitted from the photograph, but can be seen in Fig. 9 below.)

The paper label on the top cover identifies this as the "Bay State" No. 19 Socket Wrench Set, and the text below notes the "Allen Process Sockets".

The socket sizes are, from the left in the back, 7/16, 1/2, 9/16, 19/32, 5/8, 11/16, 3/4, and 25/32. In the front the sizes from the left are 13/16, 11/16 square, 19/32 square, and 1/2 square, followed by a 5/8 universal socket and a 7/16-hex to 5/8-hex adapter plug.

The universal is composed of two pieces, a 7/16-hex drive 5/8 universal socket, and a 7/16-hex to 5/8-hex adapter visible at the right.

The tools in the front bay are the long extension, the handle bar for the ratchet, and the Ell handle. The overall lengths are 9.4 inches for the extension, 7.4 inches for the handle bar, and 7.4 inches for the Ell handle. All of the tools and sockets have a plain steel finish.

The set was supplied in a wooden box with finger-jointed corners, with a wooden organizer for the sockets. The overall dimensions are 10.5 inches wide by 4.5 inches deep by 2.5 inches high.

Allen Mfg. 7/16-Hex Drive Ratchet Head and Handle Bar from No. 19 Socket Set

Fig. 9. Allen Mfg. 7/16-Hex Drive Ratchet Head and Handle Bar, with Inset for Top View, ca. 1922 to Mid 1920s.

Fig. 9 shows the 7/16-hex drive ratchet head from the No. 19 set with its drive plug and handle bar.

The inset shows a top view of the ratchet body, illustrating the 7/16-hex broached drive opening in the top. This opening allowed the ratchet head to be used as an inline adapter, or as a (somewhat clunky) sliding Tee head.

The ratchet is reversible by lifting the pawl thumbscrew and rotating the pawl 180 degrees.

The ratchet head has a diameter of 1.3 inches and a height of 1.8 inches, and the length of the handle bar is 7.4 inches. Both tools have a plain steel finish.

The ratchet head is basically an inline ratchet adapter with a provision to be driven either by a cross-bar handle or by an Ell handle. The ratchet is described by patent 1,371,350, filed by Solomon A. Campbell and issued in 1921.

In 1922 Campbell filed for patent 1,489,696, which describes the ratchet head in conjunction with additional tools, including a universal joint.

Allen Mfg. 7/16-Hex Drive Universal and Adapter Plug from No. 19 Socket Set

Fig. 10. Allen Mfg. 7/16-Hex Drive Universal and Adapter Plug, ca. 1922 to Mid 1920s.

Fig. 10 shows the 7/16-hex drive universal and adapter plug from the No. 19 set.

The overall length is 3.0 inches, and the finish is plain steel.

The two-piece design of this universal meant that the set also had a 5/8 universal socket, a potentially useful size for some maintenance tasks.

Allen Mfg. 7/16-Hex Drive Sockets from No. 19 Socket Set

Fig. 11. Allen Mfg. 7/16-Hex Drive Sockets, with Inset for Top View, ca. 1922 to Mid 1920s.

Fig. 11 shows the three largest 7/16-hex drive sockets from the No. 19 set.

The socket sizes are, from the left, 13/16, 25/32, and 3/4. The sockets are marked only with the fractional size.

The inset shows the interior of the sockets, with no metal chips or other signs of broaching. However, the circular scrape marks at the bottom of the opening show that the socket blank was drilled out before being formed around a mandrel.

Allen Mfg. 7/16-Hex Drive "Bay State" No. 20 Socket Set

Fig. 12. 1922 Catalog Listing for Allen "Bay State" No. 20 Set.

Fig. 12 shows a catalog listing for the Allen "Bay State" No. 20 socket set, as published on page 27 of the Allen catalog from around 1922.

This was the company's largest set, and it builds on the No. 19 set by adding a speeder and one additional (7/8) hexagon socket.

The illustration shows the distinctive label in the center of the lid, with "Bay State Socket Wrench Set" along the diagonal.

We have an example of an Allen No. 20 socket set and are preparing it for display.

Later Production

In 1986 Allen Manufacturing became part of the Danaher conglomerate, and the Allen brand was used for a line of wrenches and socket tools.

Allen 20318 18mm Combination Wrench

Fig. 14. Allen 20318 18mm Combination Wrench, with Insets for Back Side and Edge View.

Fig. 14 shows an Allen 20318 18mm combination wrench, stamped with the metric size and "Allen" logo on the shank, with the "Allen" logo and "U.S.A." on the opposite side.

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

Allen 10909 1/4-drive Round-Head Ratchet

Fig. 15. Allen 10909 1/4-Drive Round-Head Ratchet, with Insets for Back Side and Edge View, 2002.

Fig. 15 shows an Allen 10909 1/4-drive round-head ratchet, stamped with the "Allen" logo and "USA" on the shank, with "Forged" and the model number on the opposite side.

The overall length is 5.2 inches, and the finish is chrome plating.

The back side is also marked with a Snap-on style date code for 2002. Danaher provided extensive contract production services and apparently provided date codes for some products.