The Frank Mossberg Company

Table of Contents

• Introduction
• Early Tools
• Sockets and Drive Tools
• Fixed Socket Wrenches and Specialty Tools
• The APCO Merger and Later Tools
• References and Resources
• What's New (Last Updated Apr. 6, 2008)
  Recent changes to this page:

  • 04/06/2008: Added a Mossberg "Sterling" No. 2 Bicycle Wrench.
  • 04/02/2008: Added a Mossberg No. 654 Valve Spring Lifter.
  • 03/29/2008: Added discussion of Pressed-Steel Socket Sizes.
  • 03/09/2008: Added a Mossberg Z-Shaped 19/32 Double Socket Wrench.
  • 03/04/2008: Added a Mossberg 371 11/16-Drive Adapter.
  • 01/31/2008: Added a Mossberg No. 355 Non-Reversible Ratchet.
  • 01/25/2008: Added a APCO-Mossberg 3014 Offset Box Wrench.
  • 01/23/2008: Added a Mossberg 715B Open-End Wrench.
  • 01/07/2007: Updated catalog resources.
  • 01/03/2007: Updated catalog resources.
  • 11/30/2007: Added a Mossberg Z-Shaped 17/32x21/32 Double Socket Wrench.
  • 11/09/2007: Added a Mossberg 2149 Socket Wrench.
  • 08/13/2007: Added a Mossberg 260-A Open-End Wrench.
  • 07/18/2007: Added a APCO-Mossberg 974 Single-Offset Box Wrench.
  • 05/21/2007: Added a Mossberg Male Drive Sockets.
  • 05/04/2007: Added a Mossberg 645 Ratcheting Box Wrench.
  • 05/03/2007: Added an APCO Early Double-Hex Box Wrench.
  • 02/19/2007: Added a Mossberg No. 1235 S-Shaped Wrench.
  • 02/03/2007: Added a Mossberg No. 234 Open-End Wrench.
  • 01/09/2007: Added a Mossberg F-2 Bicycle Wrench.
  • 01/04/2007: Added a Mossberg No. 11 Diamond Bicycle Wrench.
  • 11/29/2006: Added a Mossberg No. 1 Sterling Bicycle Wrench.
  • 11/21/2006: Added an Mossberg A1 Bicycle Wrench and a Mossberg Folding Drive Handle.
  • 11/19/2006: Added a APCO-Mossberg 1/2-Drive Extension.
  • 11/15/2006: Added a Mossberg No. 355 Non-Reversible Ratchet.
  • 11/14/2006: Added a Mossberg 624 Ratcheting Connecting-Rod Wrench.
  • 11/13/2006: Added Mossberg No. 363 Speeder Socket Wrench, a Mossberg No. 367 1/2-Drive Speeder, and a APCO-Mossberg 976 Single-Offset Wrench.
  • 11/12/2006: Added Mossberg Forged Heavy-Duty Sockets.
  • 11/11/2006: Added a Mossberg 422 Spark Plug Socket.
  • 11/10/2006: Added a Double-Male Universal.
  • 11/09/2006: Started patent table, added a No. 351 Extension and a 1/2-Drive Socket.
  • 11/08/2006: Added a No. 10 Socket Set.
  • 08/19/2006: Added a rare 631 Ratcheting Socket Wrench.
  • 08/17/2006: Added a 623 Socket Wrench.
  • 08/15/2006: Added page, no content yet.

Introduction

Company History

Frank Mossberg was a notable inventor and businessman in Attleboro, Massachusetts, a center for jewelry manufacturing in the 19th century. His earliest business venture was founded in 1889 as the Mossberg Wrench Company, and initially was a maker of tools for the jeweler's trade. In the early 1890s the company began producing several styles of adjustable bicycle wrenches, a type of tool very popular at the time. Patent records from 1892 show assignment to a Mossberg Manufacturing Company, but it's not known whether this was a separate business entity.

In 1899 Frank Mossberg and other investors founded the Frank Mossberg Company to manufacture tools, and the company began production of pipe wrenches, bicycle wrenches, and related tools. This new company operated independently of Mossberg's earlier business(es), but in 1901 the operations of the latter were merged into the Frank Mossberg Company. By the early 1900s the company was producing bicycle wrenches in a number of styles, with names such as Sterling and Diamond.

In 1908 the company purchased a line of automotive socket wrenches called "Auto-Cle" from the Quincy, Manchester, Sargent Company. These socket wrench sets consisted of pressed-steel sockets with a ratcheting drive tool, and were based on patents #751,055 and #RE12,379, issued in 1904 and 1905 respectively. The Auto-Cle acquisition was the starting point for a very successful line of socket wrench products, and Mossberg made numerous improvements and additions over the years.

The expansion of the automobile industry created great demand for automotive service tools, and in the years from 1910 to 1920 the Frank Mossberg Company became a significant maker of automotive specialty tools. These tools consisted primarily of fixed socket wrenches in many shapes and sizes, and Mossberg was probably second only to Walden-Worcester as a producer of such tools.

During the 1920s the company continued to expand its automotive service tools line. In 1927 the company was reorganized as the APCO-Mossberg Company, apparently by merger with APCO, although currently no information has been found regarding the other entity.

Sometime during the 1930s APCO-Mossberg decided to drop their general service tools, perhaps because of excess competition, and became instead a specialized maker of torque measurement products. The APCO-Mossberg torque products remained in production for many years.

Patents

Trademarks

A search of the USPTO trademark records found only one trademark registered by Frank Mossberg, the M-Diamond logo. The trademark was filed in 1907 and listed the first use as November 1902.

Early Tools

"Sterling" No. 1 Bicycle Wrench

Fig. 1A. Mossberg "Sterling" No. 1 Bicycle Wrench, ca. 1900-1902.

Fig. 1A shows a Mossberg "Sterling" No. 1 bicycle wrench, stamped "Manf'd by Frank Mossberg Co." and "Attleboro, Mass. U.S.A" with a "Pat. Nov. 13, 00" patent date.

The overall length is 5.0 inches, and the finish is fully polished with nickel plating.

The patent date corresponds to patent #661,810, filed by Frank Mossberg in 1900 and issued later that year.

The absence of the M-Diamond trademark suggests that this is an early tool, made before the general use of the trademark logo.

"Sterling" No. 2 Bicycle Wrench

Fig. 1B. Mossberg "Sterling" No. 2 Bicycle Wrench.

Fig. 1B shows a later Mossberg "Sterling" No. 2 bicycle wrench, stamped with the M-Diamond logos on either side of the model number, with "Manf'd by Frank Mossberg Co." and "Attleboro, Mass. U.S.A" at the end of the shank.

The overall length is 6.5 inches, and the finish is polished nickel, but with some loss due to wear and rust.

The wrench is also stamped with a "Pat. Nov. 13, 00" patent date, corresponding to patent #661,810, filed by Frank Mossberg in 1900 and issued later that year.

"Diamond" No. 11 Bicycle Wrench

Fig. 2. Mossberg "Diamond" No. 11 Bicycle Wrench.

Fig. 2 shows a Mossberg "Diamond" No. 11 bicycle wrench, marked "Frank Mossberg Co." and "Attleboro Mass. U.S.A" with M-Diamond logos on each side, and with patent notations "Pat'd. Nov. 13, 00" and "Pat'd. Mar. 11, 02".

The overall length is 5.5 inches, and the finish is nickel plating.

The patent dates refer to patents #661,810 and #695,072, both of which describe methods of constructing adjustable wrenches of this design.

A-1 Bicycle Wrench

Fig. 3. Mossberg A-1 Bicycle Wrench.

Fig. 3 shows a Mossberg A-1 bicycle wrench, marked with the M-Diamond logo and patent notations "Pat. Nov. 13, 00 Mar. 11, 02".

The overall length is 5.0 inches, and the finish is nickel plating.

The patent dates refer to patents #661,810 and #695,072, both of which describe methods of constructing adjustable wrenches of this design.

F-2 Bicycle Wrench

Fig. 4. Mossberg F-2 Bicycle Wrench.

Fig. 4 shows a Mossberg F-2 bicycle wrench, stamped with two M-Diamond logos and the patent notations "Pat. Nov. 13, 00 Mar. 11, 02".

The overall length is 5.5 inches, and the finish is nickel plating.

K-8 Bicycle Wrench

Fig. 5. Mossberg K-8 Bicycle Wrench, ca. 1905.

Fig. 5 shows a rare Mossberg K-8 bicycle wrench, marked "Made in U.S.A." with the M-Diamond logo, and with patent notations "Patd. Nov. 13, 00 Mar. 11, 02".

The overall length is 7.9 inches.

One unusual feature is that the wrench body appears to be constructed of a copper alloy, as can be seen in the bright areas where the greenish tarnish has been removed.

234 Open-End Wrench

Fig. 6. Mossberg No. 234 1/2x19/32 Open-End Wrench.

Fig. 6 at the left shows a Mossberg No. 234 1/2x19/32 open-end wrench of stamped steel construction, marked with the M-Diamond logo.

The overall length is 4.9 inches, and the finish is plain steel.

260-A Open-End Wrench

Fig. 7. Mossberg No. 260-A 5/8x15/16 Open-End Wrench.

Fig. 7 at the left shows a Mossberg No. 260-A 5/8x15/16 open-end wrench of stamped steel construction, marked with the M-Diamond logo.

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

715B Open-End Wrench

Fig. 8. Mossberg No. 715B 1/2x11/16 Open-End Wrench.

Fig. 8 shows a Mossberg No. 715B 1/2x11/16 open-end wrench of stamped steel construction, marked "Made in U.S.A." with the M-Diamond logo.

The overall length is 5.9 inches, and the finish is plain steel.

1235 S-Shaped Open-End Wrench

Fig. 9. Mossberg No. 1235 1/2x9/16 S-Shaped Open-End Wrench.

Fig. 9 at the left shows a Mossberg No. 1235 1/2x9/16 S-shaped wrench of stamped steel construction, marked with the M-Diamond logo.

The overall length is 4.9 inches, and the finish is plain steel.

551 Single Open-End Wrench

Fig. 10. Mossberg 551 25/32 Single Open-End Wrench.

Fig. 10 shows a Mossberg 551 25/32 open-end wrench of stamped steel construction, marked with the M-Diamond logo.

The overall length is 6.4 inches, and the finish is plain steel.

645 Ratcheting Box Wrench for Ford Applications

Fig. 11A. Mossberg 645 11/16 Ratcheting Box Wrench, with Inset for Side View.

Fig. 11A shows a Mossberg 645 11/16 ratcheting box wrench intended for servicing Model T reverse and brake bands. The handle is stamped "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." with the M-Diamond logo, and the application is noted as "For Ford Reverse & Brake Pedal Bands".

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

The wrench is also marked with a "Pat. Dec. 28, 1915" patent notice, which corresponds to patent #1,165,995. The patent describes the construction of a simple and inexpensive ratchet, as needed for the high-volume but cost sensitive Model T tools market.

No. 654 Valve Spring Lifter

Fig. 11B. Mossberg No. 654 Valve Spring Lifter, with Inset for Top View, ca. 1914-1920.

Fig. 11B shows an early Mossberg No. 654 valve spring lifter, stamped "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." with the M-Diamond logo, and with a "Pat. Jul. 28, 14" patent notice.

The overall length is 7.1 inches, and the finish is nickel plating.

The patent date corresponds to patent #1,105,096, filed by S.C. North in 1912 and issued in 1914.

Early 17/32x21/32 Z-Shaped Double Socket Wrench

Fig. 12. Mossberg 17/32x21/32 Z-Shaped Double Socket Wrench, with Insets for Socket Detail, ca. 1910-1918.

Fig. 12 shows a Mossberg 17/32x21/32 double socket wrench with a Z-shaped handle, marked with the M-Diamond logo on the shank and sockets.

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

As can be seen from the photograph, this wrench was constructed by crimping two pressed-steel sockets to a bent steel handle.

This wrench was one of the tools included in the Mossberg No. 17 wrench kit for the Ford Model T, a set of five fixed socket wrenches in a canvas roll. The No. 17 set is listed for $2.00 in a 1916 Central Automobile Supply catalog.

Early 19/32x19/32 Z-Shaped Double Socket Wrench

Fig. 13. Mossberg 19/32x19/32 Z-Shaped Double Socket Wrench, with Insets for Socket Detail, ca. 1916-1918.

Fig. 13 shows another example of the Mossberg Z-shaped wrenches, a double socket wrench with 19/32 sockets of square and oval cross-section, stamped with the M-Diamond logo on the shank.

The overall length is 8.6 inches, and the finish is plain steel.

This wrenche was intended for servicing the Model T main bearings, which used oval-shaped nuts on earlier models and square nuts after around 1916.

This wrench was one of the tools included in the Mossberg No. 17 wrench kit for the Ford Model T, a set of five fixed socket wrenches in a canvas roll.

Sockets and Drive Tools

Mossberg was a pioneer in the development of sockets and drive tools. Their early sockets were made of pressed steel, with the drive ends cleverly sized to allow being driven either on the outside (approximately 11/16 square), or from the inside as 1/2 square drive. By 1912 Frank Mossberg had filed a patent for a reversible ratchet to drive the sockets, and the resulting socket sets with reversible ratchets became best sellers of their time.

Pressed-Steel Socket Sets

We'll begin this section with a look at some of the Mossberg early pressed-steel socket sets.

Pressed-Steel Socket Sizes

Before proceeding to show examples of the socket sets, we first need to discuss the sizing for pressed-steel sockets, as this is an area that's sure to cause confusion. Readers familiar with early Model T socket sets may have wondered about the numerous "oddball" socket sizes in 32nds, sizes such as 17/32 or 23/32 that are seldom seen today. Based on the socket sizes, you might have concluded that the early automobiles used a lot of strange fastener sizes.

However, if you check the open-end wrenches from the same time era, these tools don't include all of the opening sizes seen on sockets. (Keeping in mind that wrench openings were marked by a U.S.S. or S.A.E. size.) So if a Model T really used 17/32 or 23/32 nuts, why weren't these sizes available in open-end wrenches?

This discrepancy turns out to be due to pressed-steel socket sizes being specified as 1/32 oversize, apparently an allowance for the manufacturing tolerance. This means that a 17/32 pressed-steel socket would be specified for an (across-flats) 1/2 inch nut, for which a modern 1/2 socket would work fine. This same nut would use an open-end wrench marked as "1/4 U.S.S." or "5/16 S.A.E." under the old size conventions.

So in reality the Model T didn't have any 17/32 or 23/32 nuts. The early automobiles used a mix of fasteners with sizes following the U.S.S., S.A.E., or Hex Cap Screw conventions, which use a few of the 32nd sizes, but the "strange" sizes appear only when the 1/32 oversize socket allowance is added. Open-end wrenches (and modern sockets) don't need to use an explicit oversize allowance, as the manufacturing tolerances allow for a small oversize to be buried in the nominal size.

Table 2. Pressed-Steel Socket Sizes for U.S.S., S.A.E., and Hex Cap Screw Nuts

To help further clarify the situation, we've added a table showing the recommended pressed-steel socket size for the commonly used fasteners, along with the corresponding across-flats nut (or bolt) size. The information in Table 2 is from a 1922 Marwedel catalog listing for Mossberg sockets, and the catalog clearly states that a 1/32 clearance will be added if the sockets are ordered by nut size.

Keep in mind that the above table applies only to pressed-steel sockets -- later sockets were made with a broaching or forging technology that didn't require such a large oversize allowance.

No. 310 1/2-Drive Folding Offset Handle

Fig. 14. Mossberg No. 310 1/2-Drive Folding Offset Handle, ca. 1910-1915.

Fig. 14 shows an early 1/2-drive Mossberg folding handle, marked "Man'f'd by Frank Mossberg Co." and "Attleboro, Mass." with the M-Diamond logo. Although not marked with a model number, this was identifed as a No. 310 handle by a catalog reference.

The overall length is 6.0 inches folded and 10.9 inches when fully extended. The finish appears to be a thin dark lacquer.

The handle is also marked with the patent date "Pat'd. Feb. 15-10", referring to patent #949,083.

Mossberg Early Pressed-Steel Socket Set

This next figure shows an early Mossberg pressed-steel socket set in a leather case. The set has not yet been identified from a catalog reference, but consists of a folding drive handle with a selection of sockets.

No. 7 Socket Set

The Mossberg No. 7 socket set was one of their more modest collections, consisting of two drive tools and 15 pressed-steel sockets in a wooden box. The drive tools are the No. 320 Ell handle and the No. 324 Tee handle; no ratchet was included in this set.

The socket sizes (all hex) are 13/32, 15/32, 17/32, 19/32, 5/8, 21/32, 23/32, 25/32, 13/16, 27/32, 29/32, 1 inch, 1-1/32, and 1-3/32. Also included is one 29/32 deep spark-plug socket.

Our set is currently being prepared for display.

No. 10 Pressed-Steel Socket Wrench Set

Fig. 17. Mossberg No. 10 Pressed-Steel Socket Set, ca. 1913-1923.

Fig. 17 shows an example of an early pressed-steel socket set, a Mossberg No. 10 socket set in a wooden box.

The original contents of the set were obtained from a 1922 catalog listing, and consisted of a ratchet, extension, universal, 19 standard hex sockets, two spark plug (deep) sockets, and an offset screwdriver. Our set as acquired is reasonably complete, but is missing the offset screwdriver and a few sockets, and at least one other socket is a later replacement.

The standard socket sizes (all hex) were 15/32, 1/2, 17/32, 19/32, 5/8, 21/32, 11/16, 23/32, 25/32, 13/16, 27/32, 7/8, 29/32, 31/32, 1 inch, 1-1/32, 1-3/32, 1-5/32, and 1-9/32. The set as pictured is missing the 15/32, 1/2, 27/32, and 1 inch sizes, and a 9/16 socket has been added.

The two spark plug sockets have sizes 29/32 and 1-5/32, and are shown in detail in the figures below.

Fig. 18 and Fig. 16 below show the decals glued to each end of the box, and it's fortunate that there are two, because both decals have suffered varying amounts of wear and damage over the years.

Fig. 18. First Decal from Mossberg No. 10 Socket Set.

Fig. 19. Second Decal from Mossberg No. 10 Socket Set.

Using both examples to fill in for the missing areas, the upper part of the decal reads "No. 10 Socket Wrench Set" with the M-Diamond logo (in red) in the center. The lower part reads "Made by Frank Mossberg Co." with "Attleboro, Mass. U.S.A." (partially missing) at the bottom.

No. 350 11/16-Drive Ratchet

Fig. 20. Mossberg No. 350 Ratchet, 1913+.

Fig. 20 shows the Mossberg No. 350 ratchet from the No. 10 set, marked "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." with the M-Diamond logo.

The overall length is 10.0 inches, and the finish appears to be nickel plating.

The ratchet is also marked with the patent notice "Pat. Nov. 11, 1913", which refers to patent #1,078,059, issued to Frank Mossberg and assigned to the company.

The large opening of the ratchet (approximately 11/16) is sized to drive the sockets from the outside, and is fitted with a friction ball to help secure the socket. This 11/16 drive size was a standard for the early pressed-steel socket sets, and the sockets and drive tools from all makers were generally interchangeable. Since the sockets could also be driven by the 1/2 square inside opening, the sockets could be regarded as both 11/16-drive and 1/2-drive.

No. 351 11/16-Drive Extension

Fig. 21. Mossberg No. 351 Extension.

Fig. 21 shows the Mossberg No. 351 extension included in the No. 10 set, marked "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." with the M-Diamond logo.

The overall length is 9.4 inches, and the finish appears to be nickel plating.

The extension has a distinctive design that makes use of the inner and outer drive capabilities of the sockets. The large end of the extension is sized like the socket drive ends, and the other end terminates in a 1/2-drive stud with a friction ball. This design allows several different usage patterns.

One typical usage would be to drive the large end of the extension directly with the ratchet, with the male end driving a socket from the inside. A second usage pattern would be needed to connect the double-male universal joint with the extension. For this case, the universal joint would be inserted in the socket and the large end of the extension, and the ratchet would then drive the male stud of the extension using another socket as a shim.

No. 336 Double-Male Universal

Fig. 22. Mossberg No. 336 Double-Male Universal.

Fig. 22 shows the double-male universal from the No. 10 set, unmarked but identified as a Mossberg No. 336 in the catalogs.

The overall length is 3.8 inches, and the finish is nickel plating.

The male drive studs of the universal are 1/2 inch square, close enough to the industry standard to allow operation with modern sockets. The universal connects to the Mossberg sockets using the inside drive opening, and the connection to the No. 350 ratchet is made by inserting a spare socket as a shim.

402 29/32 Spark Plug Socket

Fig. 23. Mossberg 402 29/32 Spark Plug Socket, with Insets for Broach and Drive End.

Fig. 23 shows a Mossberg 402 29/32 spark plug socket, marked "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." on one face, with the fractional size on another face.

The overall length is 3.5 inches, and the finish is plain steel.

The insets show the hex opening and square drive ends.

This socket was acquired as part of the Mossberg No. 10 Socket Set shown above.

422 1-5/32 Spark Plug Socket

Fig. 24. Mossberg 422 1-5/32 Spark Plug Socket.

Fig. 24 shows a similar Mossberg 422 1-5/32 spark plug socket, marked "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." on one face, with the fractional size on another face.

The overall length is 3.9 inches, and the finish is plain steel.

This socket was acquired as part of the Mossberg No. 10 Socket Set shown above.

No. 30 Socket Set

The Mossberg No. 30 socket set was a compact collection intended for Ford owners. The set consisted of a No. 355 ratchet handle, No. 351 extension, No. 336 universal, and eleven pressed-steel sockets.

The sockets include the eight regular hex sizes 15/32, 17/32, 19/32, 21/32, 23/32, 25/32, 29/32, and 31/32, plus a 31/32 deep spark plug socket. Also included (at least in earlier sets) is a 19/32 oval socket for the early Ford main-bearing bolts, plus a 19/32 square socket for later Fords.

No. 355 Ratchets

Fig. 26. Mossberg No. 355 Ratchet.

Fig. 26 shows a Mossberg No. 355 non-reversible ratchet, marked "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." with the M-Diamond logo.

The overall length is 8.6 inches, and the finish is plain steel.

The ratchet is also marked with a "Pat. Pend." notice, but the corresponding patent is not yet known. It's possible that this ratchet is covered by one of the known Mossberg ratchet patents, or there may be another patent waiting to be found.

Fig. 27. Mossberg No. 355 Ratchet.

Fig. 27 shows another example of the Mossberg No. 355 ratchet, similar to the previous figure but with a painted finish. The handle is stamped "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." with the M-Diamond logo, and with a "Pat. Pend." notice.

This ratchet was acquired as part of a Mossberg No. 30 socket set, which will be displayed at a later time.

Later Socket Technology

Mossberg No. 360 Short Speeder Handle

Fig. 28. Mossberg No. 360 Short Speed Handle, with Inset for Detail, ca. 1918-1920.

Fig. 28 shows a 1/2-drive Mossberg No. 360 short speed handle or brace, marked "Made in U.S.A." with the M-Diamond logo.

The overall length is 11.5 inches.

The drive end has a detent ball and four pinched tabs as stops, typical construction for early tools of this type.

The circular end cap is marked "Patent Pending", and a similar but later Mossberg tool showed the patent date to be March 20 of 1920. A search of the patent records found the corresponding patent to be #1,335,408, titled "Brace Construction" and issued to W.I. Tuttle. Based on the filing date of October 3 in 1918, this particular tool was likely made between 1918-1920.

Mossberg No. 363 Speeder Socket Wrench

Fig. 29. Mossberg No. 363 Speeder Socket Wrench, with Insets for Socket and Marking Detail.

Fig. 29 shows a Mossberg No. 363 speeder socket wrench with a 49/64 socket, marked "Made in U.S.A." with the M-Diamond logo. The speeder has a throw of 4.2 inches and an overall length of 13.0 inches.

This speeder wrench is basically a standard 1/2-drive short brace with a permanently attached socket. The rotating hand grip and end piece are made of seamless tubing, swaged to the shank diameter, and the hand grip is held in place by two pins (not shown in photograph). The finish is nickel plating.

The left inset provides a close-up of the socket attachment, showing a standard socket attached with a pin to the square-drive speeder. The socket is marked "Made in U.S.A." with the fractional size (49/64) and the M-Diamond logo, the standard markings for Mossberg sockets.

Mossberg No. 367 1/2-Drive Speeder

Fig. 30. Mossberg No. 367 1/2-Drive Speeder, with Insets for Marking Detail, ca. 1922-1929.

Fig. 30 shows a 1/2-drive Mossberg No. 367 speeder, marked "Frank Mossberg Corp." and "Attleboro, Mass. U.S.A." with the M-Diamond logo. The speeder has a throw of 4.2 inches and an overall length of 19.6 inches.

The rotating end piece is constructed from rolled sheet metal held in place with crimped end caps. Although not noted on this tool, the handle construction is covered by patent #1,438,970, issued to W. Tuttle in 1922.

Rotating hand grips of this type are characteristic of Mossberg's construction in the mid to late 1920s.

Mossberg Forged Sockets

Fig. 31. Mossberg Forged Sockets, with Inset for Broaching.

Fig. 31 shows two Mossberg forged sockets, marked "Made in U.S.A." with the M-Diamond logo.

The fractional sizes are marked but a bit difficult to read. The left hand socket marking appears to be 1-1/64 and measures 1.016 inches, and the right hand socket is apparently 1-9/64 and measures 1.140 inches.

Note that the intended service size for these sockets would have been 1 inch and 1-1/8 respectively. With the forging technology used for these sockets, Mossberg had been able to reduce the oversize allowance to 1/64.

Although the sockets are constructed with a square base resembling the pressed-steel sockets, these sockets were designed to be driven by the 1/2-square inner opening. Note that a hole has been drilled in the side to help secure the socket with a friction ball.

Mossberg Male Drive Sockets

Fig. 32. Mossberg Male Drive Sockets, with Insets for Broaching and Marking Detail.

Fig. 32 shows a group of four Mossberg male drive sockets, marked on the base with the M-Diamond logo and fractional size.

The sizes are, from the left, 7/16 square, 7/16 hex, 11/16 hex, and 31/32 hex.

Alloy Steel Sockets

In later years Mossberg recognized that pressed-steel sockets could not offer the strength and durability needed professional service, and the company began producing heavy-duty machined sockets made of chrome molybdenum steel. These sockets were offered in sets of varying size.

Mossberg 1/2-Drive 5/8 Alloy-Steel Socket

Fig. 33. Mossberg 1/2-Drive 5/8 Socket, with Inset for Broaching.

Fig. 33 shows a 1/2-drive Mossberg 5/8 hex socket, marked with the fractional size and M-Diamond logo.

This socket is an example of the chrome molybdenum alloy steel sockets produced by Mossberg.

Mossberg 371 11/16-Drive To 1/2-Drive Adapter

Fig. 34. Mossberg 371 Drive Adapter, with Inset for Top View, ca. 1920s.

Fig. 34 shows a Mossberg 371 adapter to convert 11/16 female drive to 1/2-drive, marked on the top with the M-Diamond logo.

This adapter allows the older Mossberg 11/16 female drive ratchets (e.g. No. 350) to be used with the newer 1/2-drive sockets.

Fixed Socket Wrenches and Specialty Tools

Mossberg 623 Socket Wrench

Fig. 35. Mossberg 623 5/8 Socket Wrench, with Inset for Detail.

Fig. 35 shows a Mossberg 623 6-point 5/8 socket wrench with an offset curled-bar handle. The wrench is marked "Frank Mossberg Co." and "Attleboro, Mass. U.S.A.", with "Made in U.S.A." and the M-Diamond logo. The overall length is 10.4 inches.

The finish is a heavy nickel plating. The offset handle was designed for clearance in connecting-rod applications.

Mossberg 2149 Socket Wrench

Fig. 36. Mossberg 2149 3/4 Offset Socket Wrench, with Inset for Construction Detail.

Fig. 36 shows a Mossberg 2149 offset socket wrench with a 3/4 hex opening, stamped "Mossberg Corp." and "Attleboro, Mass. U.S.A." with the M-Diamond logo.

The overall length is 10.0 inches, and the finish is a heavy nickel plating.

The inset shows the hex opening forged into the handle.

Mossberg 624 Ratcheting Socket Wrench

Our next figure shows the fancy version of a connecting-rod wrench, with a built-in ratchet for more convenient operation.

Fig. 37. Mossberg 624 5/8 Ratcheting Socket Wrench, with Inset for Top View.

Fig. 37 shows a Mossberg 624 5/8 ratcheting socket wrench, marked "Frank Mossberg Co." and "Attleboro, Mass. U.S.A." with the M-Diamond logo. The overall length is 10.6 inches, and the finish shows some traces of the original nickel plating.

The ratchet mechanism is similar to that used on older bit braces, with dual pawls alternately deactivated by a rotating ring. The selector ring actually has three modes of operation, with one position leaving both pawls engaged so that the socket is locked in place.

Mossberg 630 Triple-Socket Wrench

Fig. 38. Mossberg 630 (9/16x11/16)x5/8 Triple Socket Wrench, with Inset for Detail.

Fig. 38 shows a Mossberg 630 triple-socket wrench with (measured) sizes (9/16x11/16)x5/8, marked with the M-Diamond logo.

The overall length is 10.3 inches.

Mossberg 631 Ratcheting Socket Wrench

Fig. 39. Mossberg 631 19/32x5/8 Ratcheting Double-Socket Wrench, with Inset for Side View.

Fig. 39 shows a rare Mossberg 631 double-socket ratcheting wrench, marked "Made in U.S.A." with the M-Diamond logo. The socket sizes were measured as 19/32 and 5/8 (or possibly 21/32).

The overall length is 9.8 inches, and the finish is polished nickel plating.

The ratchet action can be reversed by using the rod extending from the handle. The rod is first pulled out slightly, and then turned to reverse the ratchet direction. Although the ratchet mechanism is fairly coarse with only 7 teeth, it still offers greater convenience than a fixed socket wrench.

The dual socket unit is held in place by a spring circlip, suggesting that the tool may have had interchangeable socket sizes available. (No catalog reference has been found yet for this model.)

The APCO Merger and Later Tools

In 1927 the Frank Mossberg Company merged with APCO to become the APCO-Mossberg Company. Currently we don't have much information on the APCO organization, but it was apparently a company specializing in automotive service tools and parts, especially for the Ford Model T. (The name APCO appears to be an acronym for Auto Parts Company.)

APCO tools are mentioned in some early automotive specialty catalogs. One notable product was an offset box wrench for Model T connecting-rod bolts, offered as early as 1922 and currently the earliest known box wrench made with a double-hex (12-point) broaching. An example is shown in the next figure.

APCO Early 5/8 Double-Hex Offset Box Wrench

Fig. 40. APCO Early 5/8 Offset Box-End Wrench, with Inset for Side View, ca. 1922.

Fig. 40 shows a rare early APCO 5/8 double-hex (12-point) offset box wrench, marked with "APCO" and "Pat. Applied For" forged into the handle.

The overall length is 6.7 inches, and the finish is plain steel.

This model was listed in the Western Auto 1922 "Ford Owner's Supply Book" catalog for connecting-rod applications.

The patent pending notice is believed to refer to patent #1,424,069, issued to F.W. Blackmar in 1922. The patent describes the construction of deep offset wrenches with 12-point openings and has a rather interesting history, as it was later acquired by Snap-On around 1930.

APCO-Mossberg 974 Single-Offset Box Wrench

Fig. 41. APCO-Mossberg 974 5/8 Single-Offset Box-End Wrench, with Insets for Side View and Reverse Detail.

Fig. 41 shows a rare Mossberg 974 5/8 single-offset box wrench, stamped "Chrome Molybdenum" and "Patent No. 1424069" on the top, with "APCO-Mossberg" and "Attleboro, Mass. Made in U.S.A." on the reverse.

The overall length is 10.2 inches, and the finish is nickel plating.

The patent notice refers to patent #1,424,069, issued to F. Blackmar in 1922 and later acquired by Snap-On. The patent describes the construction of deep offset wrenches with 12-point openings, and has been noted on 12-point wrenches made by Blue Point, Bonney, and Williams, in addition to the present example.

The single-offset wrench style was popular in the late 1920s and 1930s and appears to have originated with Blue Point. Examples of single-offset wrenches from other makers include the Blackhawk 2924, Blue Point X-20, Bonney 2818, Walden-Worcester 2114, and Williams 8128.

APCO-Mossberg 976 Single-Offset Box Wrench

Fig. 42. APCO-Mossberg 976 3/4 Single-Offset Box-End Wrench, with Insets for Side View and Reverse Detail.

Fig. 42 at the left shows a rare Mossberg 976 3/4 single-offset box wrench, stamped "Chrome Molybdenum" and "Patent No. 1424069" on the top with "APCO-Mossberg" and "Attleboro, Mass. Made in U.S.A." on the reverse.

The overall length is 11.4 inches, and the finish is plain steel.

APCO-Mossberg 3014 Specialty Box Wrench

Fig. 43. APCO-Mossberg 3014 9/16x13/16 Specialty Box Wrench, with Insets for Side View and Marking Detail, ca. early 1930s.

Fig. 43 shows a rare Mossberg 3014 9/16x13/16 specialty box wrench, intended for Chevrolet connecting-rod and main bearing service. The shank is marked with the M-Diamond logo plus "APCO-Mossberg Corp." and "Attleboro, Mass. U.S.A." in forged raised letters.

The overall length is 14.0 inches, and the finish is plain steel.

APCO-Mossberg 1/2-Drive Extension

Fig. 44. APCO-Mossberg 1/2-Drive 10 Inch Extension.

Fig. 44 shows a 1/2-drive Mossberg extension, marked "APCO-Mossberg" and "Attleboro, Mass. Made in U.S.A." on the shank. The overall length is 10.0 inches, and the finish is plain steel.

References and Resources

Photographs and observations of particular tools are based on items in my personal collection.

The Frank Mossberg Company and the earlier Mossberg Wrench Company are listed in American Wrench Makers 1830-1930, 2nd Edition by Kenneth Cope (Astragal Press, 2002). The book includes information on the early history of the companies, and shows illustrations of some of the early Mossberg products, obtained from period advertisements and trade magazines. Also included are a number of patent dates.

Catalog Resources

Currently our only Mossberg catalog is the 1923 "Condensed Catalog of Wrenches and Tools", an abbreviated version of the No. 24 catalog. The catalog notes that chromium-manganese steel had been in use for socket tools for the past year, and had been very well received by their customers.

Mossberg tools were carried by a number of industrial distributors and automotive dealers, and the catalogs of these companies provide valuable information on Mossberg products.

• A 1916 catalog from Central Automobile Supply (Des Moines, Iowa) lists a number of Mossberg socket sets, including the No. 7, No. 10, No. 11, No. 14, and No. 15A sets. It also lists several models of fixed socket wrenches, including Nos. 623 and 630, plus the No. 17 set of fixed socket wrenches in a canvas roll.

• The 1919 catalog from the Chandler & Farquhar Company, an industrial distributor, lists a number of Mossberg pressed-steel socket sets. The sets include the No. 1 "Auto Cle" and Nos. 7, 9, 10, 11, 14, and 30 standard sets, plus the No. 19 and No. 20 "Large Series" sets.

• The 1921 catalog No. 2 from Cragin & Co. of Seattle lists several pages of Mossberg pressed-steel socket sets, with models including No. 7, No. 10, No. 11, No. 14, and No. 15A, plus the No. 20 "Heavy-Duty" set. One useful detail is that the catalog descriptions itemize the contents, even listing part numbers for the individual sockets.

• The 1922 catalog No. 11 from the C.W. Marwedel Company, an industrial supplier, includes several listings of Mossberg socket sets. The listings include the "Auto-Cle" socket sets No. 1 and No. 2, and two heavy-duty "Large Series" socket sets, No. 19 and No. 20.

• The 1925-26 catalog for the Williams Hardware Company (not to be confused with J.H. Williams & Co.) lists two of the Mossberg Socket Wrench Sets, the No. 10 and No. 14 models, and provides a helpful listing of the contents.

• The 1928 catalog No. 28 from the McMaster-Carr Supply Company, a Chicago-based industrial distributor, lists several pages of Mossberg tools. The catalog offers a number of socket sets based on heavy-wall chrome molybdenum sockets, including sets No. 81 and No. 82 for professional use, and smaller sets Nos. 80, 83, and 84 for automobile owners.

  Mossberg pressed-steel socket sets were also still available, and the catalog lists sets Nos. 9, 10, 13, 14, and 30, plus the No. 20 "Large Series" set. These sets were packed in steel cases at this time, instead of the wooden boxes used earlier.

Patents and Trademarks

Patent information was obtained from the U.S. Patents and Trademarks Office (USPTO) web site at uspto.gov. Patent documents were obtained from sites offering free downloads, notably freepatentsonline.com.

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