Quick-Disconnect Sockets and Drive Tools

By the mid 1920s, Blackhawk's early socket tools had matured into a full line of drive tools and sockets, including a ratchet, speeder, offset handle, sliding Tee handle, extensions, a universal, and various accessory tools. These tools were referred to as the "Quick Disconnect" line, or Q.D. for short, and were finished in black paint. Sockets with six-point (hex) or 4-point (square) broachings remained the standard until the late 1920s, when sockets with 12-point (double-hex) service openings were introduced.

In addition to improving and expanding the line of drive tools, Blackhawk added lines of heavy-duty tools in the mid 1920s. Tools in 3/4-drive became available in the 1924-1925 time frame, and extra-heavy-duty 7/8-drive tools were introduced in 1925-1926. Tools in 3/8-drive also appeared later in the decade.

It's not known exactly when the term Quick Disconnect was first used, but it was definitely in use by 1925; a Blackhawk magazine advertisement from that year prominently features the Q.D. line. Their advertisement shows a number of the Q.D. tools, including Tee-handle, sliding Tee handle, speeder, extensions, and sockets. Notably, the Tee-handle and speeder in the illustration show a rotating hand grip; see the 3310 Tee Handle for an example.

In this section we'll first examine the individual Q.D. tools, then look at some examples of Q.D. socket wrench sets (with carrying cases) dating from around 1926 to 1930.

Q.D. 1/2-Drive Socket Tools

T-4 1/2-Drive Sliding Tee Handles

The next figures show examples of the Blackhawk T4 sliding Tee handles.

Fig. 70. Blackhawk Q.D. T4 1/2-Drive Sliding Tee Handle, ca. 1925+.

Fig. 70 shows a Blackhawk T4 1/2-drive sliding Tee handle, stamped with "Blackhawk" and "Made in U.S.A." on the bar.

The overall length is 10.0 inches, and the bar has a 9/16 diameter. The finish is black paint.

Fig. 71. Blackhawk T4 1/2-Drive Q.D. Sliding Tee Handle, from No. 18-A Set, ca. 1926-1928.

Fig. 71 shows another very similar Blackhawk T4 sliding Tee handle, acquired as part of the No. 18-A set shown later.

The overall length is 10.2 inches, and the bar has a 9/16 diameter.

Note that this tool is slightly longer than the previous example.

The T4 sliding Tee handle was a standard component of some of Blackhawk's socket sets, from the earliest No. 2, No. 8, and No. 10 sets discussed in the previous section, up through the Nos. 18-A and 22-CD sets shown below.

However, early versions of the T4 sliding Tee handle were much shorter than these later bars, only around 7.5 inches, and therefore providing much less leverage for turning. The earlier bars also had a significantly smaller diameter, 7/16 compared with the later 9/16, making the later handles much stronger.

Note that these sliding Tee handles have have pinched tabs at the ends of the bar rather than ball-stops. Pinched tabs remained Blackhawk's preferred mode of production for sliding Tee handles until sometime in the late 1920s.

An earlier version of this model can be seen as the Blackhawk Early T4 Sliding Tee Handle.

T5 1/2-Drive Double-Ended Ell Handle

Fig. 72. Blackhawk T5 1/2-Drive Q.D. Double-Ended Ell-Handle.

In Fig. 72 we see another style of breaker bar, a Blackhawk T5 1/2-drive double-ended Ell-handle, marked "Made in U.S.A." and with traces of black paint.

The overall length is 10.6 inches.

This tool was acquired separately from the No. 22-CD set described below, but the model T5 was a component of the No. 22-CD and No. 22-C sets.

T6 1/2-Drive 6 Inch Extension

Fig. 73. Blackhawk T6 1/2-Drive Q.D. 6 Inch Extension.

Fig. 73 shows a Blackhawk 1/2-drive 6 inch extension, stamped with "Blackhawk" and "Made in U.S.A." on the shank.

The overall length is 6.1 inches, and the finish is black paint.

Note that this extension is constructed as a single forging (or turning), instead of the two-piece socket and square shaft used for earlier examples. In addition, the pinched tab stops have been replaced by a forged (or milled) shoulder on the drive end. An earlier example of this model can be seen as the Blackhawk Early T6 Extension.

T8 1/2-Drive 8 Inch Extension

Fig. 74. Blackhawk T8 1/2-Drive Q.D. 8 Inch Extension.

Fig. 74 shows a Blackhawk 1/2-drive 8 inch extension, stamped with "Blackhawk" and "Made in U.S.A." on the shank.

The overall length is 8.0 inches, and the finish is black paint.

Note that this extension is constructed as a single forging, instead of the socket and square shaft used for earlier examples such as the Blackhawk Early T8 Extension.

Note also that the pinched tab stops of earlier models have been replaced by a forged shoulder on the drive end.

T10 10 Inch Extensions

Fig. 75. Blackhawk T10 1/2-Drive 10 Inch Extension, ca. 1925-1930.

Fig. 75 shows a 1/2-drive Blackhawk T10 10 inch extension, stamped with "Blackhawk" and "Made in U.S.A." on the shank.

The overall length is 10.0 inches, and the finish is plain steel with traces of the original paint.

This extension was one of the tools included with the No. 22-CD set discussed below.

Fig. 76. Blackhawk T10 1/2-Drive 10 Inch Extension, ca. 1931-1933.

Fig. 76 shows a later Blackhawk T10 extension with a polished nickel finish, stamped "Made in U.S.A." on the shank.

The overall length is 9.9 inches.

The nickel finish suggests a later production date for this extension, but we don't have a specific catalog reference for the improved finish. The MG-330 catalog of 1930 still mentions a painted finish for the Q.D. line, and by 1934 the Q.D. tools had a cadmium finish and were being phased out.

An earlier example of this model can be seen as the Blackhawk Early T10 Extension.

110X 1/2-Drive Offset Handle

Fig. 77. Blackhawk 110X 1/2-Drive Q.D. Offset Handle, with Inset for Marking Detail, ca. 1928-1931.

Fig. 77 shows a Blackhawk 110X 1/2-drive Q.D. offset handle, marked "Made in U.S.A." and with a knurled handle.

The overall length is 10.5 inches.

This breaker bar was one of the tools included with the No. 22-CD set discussed below.

T114 Q.D. 1/2-Drive 14 Inch Flex-Head Handle

Fig. 78. Blackhawk Q.D. T114 1/2-Drive 14 Inch Flex-Head Handle, with Inset for Marking Detail, ca. 1931-1933.

Fig. 78 shows a Blackhawk T114 1/2-drive 14 inch flex-head handle, marked "Made in U.S.A." on the shank.

The overall length is 13.5 inches, and the finish is chrome plating.

610 1/2-Drive 19 Inch Speeder

Fig. 79. Blackhawk 610 1/2-Drive 19 Inch Speeder, with Inset for Marking Detail, ca. 1923-1926.

Fig. 79 shows an early 1/2-drive Blackhawk 610 19 inch speeder, marked "Made in U.S.A." on the shank (see inset).

The overall length is 18.9 inches, and the finish is plain steel with a few traces of the original black paint.

The drive stud uses pinched tabs as a stop, an indication of fairly early production. (Later production used a forged shoulder as a stop.) Similar construction can be seen on the Blackhawk Early 3310 Tee Handle shown later in this article.

911X 1/2-Drive Ratchet and T-13 Plug

Fig. 80. Blackhawk 911X 1/2-Drive Q.D. Ratchet, with T-13 Plug, ca. 1928-1931.

Fig. 80 shows a Blackhawk 911X 1/2-drive Q.D. ratchet with the standard T-13 plug, stamped with "Blackhawk" and "Made in U.S.A." on the handle.

The overall length is 10.0 inches.

The female-drive ratchet is reversible by pushing the plug through to the other side.

This ratchet was one of the tools included with the No. 22-CD set discussed below.

The 911X ratchet mechanism was fitted with a 14-tooth gear, a relatively coarse action, and the body was made of heavy gauge pressed steel rather than a forging. These design compromises helped to keep the cost reasonable, yet despite the simple design, the 911X model proved to be a rugged and reliable tool. Blackhawk continued production of this or very similar successor models until at least the late 1940s.

Later 911X Reversible Ratchet

The original 911X ratchets had female drive non-reversible mechanisms, requiring that the drive plug be pushed through to change direction. But toward the end of the Q.D. product life, Blackhawk updated the 911X ratchets to add a shift lever.

Fig. 81. Blackhawk 911X 1/2-Drive Q.D. Reversible Ratchet, with Inset for Back Side, ca. 1934.

Fig. 81 shows a later-model 911X reversible ratchet, with the shift lever conveniently placed on the handle. As with the earlier models, the ratchet is marked "Made in U.S.A." and has an overall length of 10.0 inches.

The finish is cadmium plating, now worn through in some areas.

In addition to making the ratchet reversible, the later models also had a 20-tooth gear for a finer action. Since the drive plug no longer needed to be pushed through, the plug was permanently crimped into the ratchet gear.

The 1934 catalog MG534 lists the 911X reversible ratchet, along with a diminishing number of other Q.D. tools, as the Q.D. line was being phased out.

T-1 15/16 Drag Link Driver

Fig. 82. Blackhawk T-1 1/2-Drive 15/16 Drag Link Driver, with Inset for Top View.

Fig. 82 shows a 1/2-drive Blackhawk T-1 15/16 drag link driver, stamped with "Blackhawk" and "Made in U.S.A." on the side.

The overall height is 1.5 inches, and the finish is plain steel.

T-2 Universal

Fig. 83. Blackhawk T-2 1/2-Drive Q.D. Universal.

Fig. 83 shows a 1/2-drive Blackhawk T-2 universal joint, stamped "Blackhawk" and "Made in U.S.A." on the body.

The overall length is 2.6 inches, and the finish is black paint.

This universal was one of the tools included with the No. 22-CD set discussed below.

T-3 Ratchet Adapters

As an alternative (or complement) to the 911X ratchet handle, Blackhawk also offered an inline ratchet adapter, which actually operated as a spring-loaded geared clutch. The next two figures show examples of the Blackhawk T-3 ratchet adapter.

Fig. 84. Blackhawk 1/2-Drive T-3 Ratchet Adapter, with Inset for Marking Detail.

Fig. 84 shows a 1/2-drive Blackhawk T-3 ratchet adapter, stamped "Blackhawk" and "Made in U.S.A." on the body, and with a "Pat. 1,443,413 Jan. 30, 1923" patent notice on the back side.

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

The patent notice on this tool was a surprise, as the patent cited was filed by J.N. Johnson in 1920 and assigned to the Snap-On Wrench Company.

This is currently the only Snap-On patent known to have been used by Blackhawk. An example of Snap-On's version of the ratchet adapter can be seen as the Snap-On No. 6 Ratchet Adapter.

In the photograph a screw head is visible below and to the left of the model number. This set screw can be removed to allow disassembly of the device, a convenience for cleaning and lubricating the adapter.

Fig. 85. Blackhawk 1/2-Drive T-3 Ratchet Adapter.

Fig. 85 shows another 1/2-drive Blackhawk T-3 ratchet adapter, stamped "Blackhawk" and "Made in U.S.A." on the body.

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

The T-3 adapter wasn't included with any of the standard socket sets sold by Blackhawk, and as a result is less commonly found than other early Blackhawk tools.

This tool is quite similar to the open-gear clutch-style ratchet adapters from other companies of that time, such as the Snap-On No. 6.

T-11 Valve Grinding Adapter

Early autombile engines required frequent valve service, and part of the job involved grinding (or lapping) the valve in place after resurfacing the seat. Valve lapping was best done using a special reciprocating hand crank tool, but socket sets often included a simple adapter tool so that a brace or speeder could be used.

Fig. 86. Blackhawk T-11 1/2-Drive Valve Grinding Adapter.

Fig. 86 shows a Blackhawk T-11 1/2-drive valve lapping attachment, marked "Made in U.S.A." and with some traces of the original black paint. The overall length is 2.6 inches.

In operation, the slotted shaft was fitted with a small crossbar to engage the valve head, and then the valve was rotated back and forth with a grinding compound (an abrasive slurry) between the valve and seat.

This tool was acquired with the tools in a No. 18-A socket set, although it was not one of the standard components of that set. The T-11 adapter was a standard part of the No. 22-CD/32-C socket sets.

Valve grinding adapters were frequently included in early socket sets, and other examples include the Indestro 642 Valve Grinding Adapter.

Rotating Hand Grips

In 1926 Blackhawk received patent #1,574,136 for a novel way to make hand-grips for tools. Blackhawk's method used crimped sheet metal so that the grip could be added after other manufacturing steps were complete; the prior art required machining a sleeve and installing it as the tool was being made.

These hand grips were used on a number of the Q.D. tools, including speeders, Tee-handles, and extensions. The patent was filed in 1922, so these handles were probably in use well before the 1926 issue date. We'll begin the figures with an early tool made before the rotating grip patent was issued.

Early 3310 1/2-Drive Tee Handle

The next two figures show examples of the 3310 Tee handle.

Fig. 87. Early Blackhawk 3310 1/2-Drive Q.D. Tee Handle, with Insets for Marking and Construction Details, ca. 1922-1926.

Fig. 87 shows an early Blackhawk model 3310 1/2-drive Tee handle, stamped with "Made in U.S.A." on the shank, and with "Patent Pending" on the rotating grip.

The overall length is 11.5 inches.

The right inset shows a close-up of the drive stud, with pinched tabs at each corner acting as a stop.

Fig. 88. Blackhawk 3310 1/2-Drive Q.D. 12 Inch Tee Handle, with Inset for Marking Detail, ca. 1928-1931.

Fig. 88 shows a later Blackhawk model 3310 1/2-drive 12 inch Tee handle, stamped with "Blackhawk" and "Made in U.S.A." on the shank, and with "Patented Feb. 23, 1926" on the rotating grip.

The overall length is 12.0 inches, and the finish is plain steel, with traces of black paint.

The drive stud on this later model uses a forged collar as a stop, instead of the pinched tabs we saw on the early model.

This Tee handle was one of the tools included with the No. 22-CD set discussed below.

500 1/2-Drive 15 Inch Brace

Fig. 89. Blackhawk Model 500 1/2-Drive 15 Inch Brace, with Insets for Detail, ca. 1928-1931.

Fig. 89 shows a Blackhawk 500 1/2-drive 15 inch brace (or short speeder), marked "Made in U.S.A." with "Patented Feb. 23, 1926" on both rotating grips.

The overall length is 15.4 inches, and the throw is 4.8 inches.

The model 500 brace had a long history at Blackhawk, as this model was one of the tools included in the early No. 10 socket sets introduced in 1919.

This particular brace was one of the tools included with the No. 22-CD set discussed below.

T15 1/2-Drive Crank Speeder

In addition to its conventional speeders and braces, Blackhawk also produced a distinctive "crank speeder" drive tool.

Fig. 90. Blackhawk T15 1/2-Drive Q.D. Crank Speeder, with Inset for Detail, ca. 1926-1929.

Fig. 90 shows a 1/2-drive Blackhawk model T15 crank speeder, marked "Made in U.S.A." with "Patented Feb. 23, 1926" on the rotating grip. The overall length is 8.0 inches.

This speeder was acquired as part of a Blackhawk No. 18-A socket set. The No. 18-A set was a smaller collection of sockets and drive tools intended for automobile owners; it was listed in a 1929 catalog, but had been discontinued in the Blackhawk catalogs by 1930.

T-60 1/2-Drive 6 Inch Extension

Fig. 91. Blackhawk T60 1/2-Drive 6 Inch Extension, ca. 1928-1931.

Fig. 91 shows a Blackhawk T-60 1/2-drive rotating-grip 6 inch extension, marked "Made in U.S.A." with "Patented Feb. 23, 1926" on the grip.

The overall length is 5.9 inches, and the finish is black paint.

This extension was one of the tools included with the No. 22-CD set discussed below.

Q.D. 1/2-Drive Sockets

Blackhawk produced Q.D. sockets in a wide range of sizes, in both hex and double-hex broachings, and also offered a smaller selection of square (4-point) sockets. Socket sets were furnished with the customer's choice of hex or double-hex sockets.

The first figure below shows some earlier examples of sockets marked with the Blackhawk company name, rather than the Arrowhead logo used beginning in 1919. The date of this change in markings is not known precisely, but probably occurred around 1925 or so.

Early Blackhawk 1/2-Drive Q.D. Hex Sockets

Fig. 92. Early Blackhawk 1/2-Drive 6-Point Sockets, ca. 1925-1927.

Fig. 92 shows a group of early Blackhawk 1/2-drive 6-point sockets, all marked "Blackhawk" and "Made in U.S.A." and with a knurled band. The sizes and models numbers are, from the left, 1 (no model), 15/16 (30), and 1 (32).

The socket on the left is likely the earliest of the lot, as it is marked with the size (1 inch) rather than a model number. The middle and righthand sockets are very similar but show model numbers, assigned as the size in 32nds.

Blackhawk 1/2-Drive Q.D. Hex Sockets

Fig. 93. Blackhawk 6-Point 1/2-Drive Q.D. Sockets, From Left: 30, 31, 32, ca. 1928-1931.

Fig. 93 shows three 1/2-drive 6-point Q.D. sockets from the No. 22-CD socket set described below, all marked "Made in U.S.A." and with a knurled band.

The models and sizes are, from the left, 30 (15/16), 31 (31/32), and 32 (1 Inch).

A comparison with the Early 6-point sockets reveals a few minor design changes. The larger sockets now have a turned-down base, and the diameter has been reduced slightly after the knurled band.

130 and 136 Spark Plug Sockets

The Q.D. line included two 1/2-drive deep sockets, intended primarily for spark-plug applications.

Fig. 94. Blackhawk 1/2-Drive Q.D. Deep Spark-Plug Sockets, ca. 1926-1927.

Fig. 94 shows the two deep sockets, both marked "Made in U.S.A." and with a knurled band. The models and sizes are, from the left, 130 (15/16), and 136 (1-1/8).

These sockets were acquired as part of the No. 18-A set discussed below. The model 136 socket was also a standard part of the No. 22-C/32-C sets.

0xx Square (4-Point) Sockets

Fig. 95. Blackhawk 4-Point 1/2-Drive Q.D. Sockets, From Left: [012], 016, 018.

Fig. 95 shows three 1/2-drive Q.D. sockets with square (4-point) broachings. All are marked "Made in U.S.A." with a knurled band, but show some differences in the finish. The models and sizes are, from the left, (no model) 3/8, 016 (1/2), and 018 (9/16).

The model 016 socket (in the middle) was part of the No. 22-CD set described below, and is finished in the standard black paint. The other two sockets were acquired separately and have a cadmium finish, indicating a somewhat later manufacturing date. However, the 3/8 socket on the left isn't marked with the expected 012 model number.

Dxx Double-Hex (12-Point) Sockets

In 1928 Blackhawk introduced its Dxx series of double-hex (12-point) Q.D. sockets, with sizes matching the standard series of hex sockets.

Fig. 96. Blackhawk Dxx Series 1/2-Drive Q.D. Double-Hex Sockets.

Fig. 96 shows a series of Blackhawk Dxx 1/2-drive double-hex (12-point) sockets, all marked "Made in U.S.A." and with varying amounts of the original black paint remaining.

In the Dxx series the "xx" number is the size in 32nds, so the models and sizes in the photograph are (from the left) D18 (9/16), D19 (19/32), D20 (5/8), D21 (21/32), and D22 (11/16).

The socket construction is cold-broached with a relieved area below the broaching to allow chip removal; this was typical construction for sockets in the late 1920s.

The Dxx sockets were standard with the Q.D. wrench sets No. 22-CD and 32-CD; however, these particular examples were acquired separately from the set described below.

Late Production D40 12-Point Socket

While we're on the topic of the Dxx sockets, let's take a quick look ahead a few years. The Q.D. series remained in production for some time after the successor Lock-On tools were developed, and the construction and finish of the Q.D. sockets were updated accordingly.

Fig. 97. Later Blackhawk D40 1-1/4 Q.D. Socket, with Inset for Broaching, ca. 1932-1935.

Fig. 97 shows a later production Dxx series socket, a Blackhawk D40 1-1/4 socket marked "Made in U.S.A." on the reduced base.

The design of this socket has been updated to resemble the 66xx series Lock-On sockets of the early 1930s; in particular, the functional knurled band of the earlier Dxx series has been replaced with a small decorative band. The finish has been updated as well, with the black painted replaced by cadmium plating.

The inset shows the socket construction, which appears to be an early hot-broach process.

T20 Universal Socket

Blackhawk's Q.D. line included universal sockets in a range of sizes from 1/2 to 7/8 inches. These sockets were available only in hex broachings.

Fig. 98. Blackhawk T20 1/2-Drive 5/8 Universal Socket, with Insets for Broaching and Marking Detail.

Fig. 98 shows a 1/2-drive Blackhawk T20 5/8 universal socket, marked "Made in U.S.A." on the base.

The 1927 Blackhawk catalog offered universal sockets in seven models: T16 (1/2), T18 (9/16), T20 (5/8), T22 (11/16), T24 (3/4), T26 (13/16), and T28 (7/8).

Q.D. Socket Wrench Sets

The previous figures have shown a number of the individual Q.D. tools, and we'll now present some examples of the socket sets containing these tools. Blackhawk offered a number of such sets, configured in various ways for different applications and budgets.

Currently we have two examples ready for display, a smaller 18-A set probably from around 1926, and a slightly later No. 22-CD/32-C model from around 1929-1930. Additional sets will be added as time permits.

No. 18-A Socket Wrench Set

The Blackhawk No. 18-A[D] socket wrench sets were smaller collections of essential tools, intended for "student mechanics and automobile owners", as a Blackhawk catalog expressed it. The set consisted of a ratchet, brace, T-slider, a crank speeder, two extensions, two spark-plug (deep) sockets, and ten regular sockets.

For our first figure we'll show an illustration of a No. 18-AD socket set from an industrial supply catalog, published in 1930, more than 75 years ago.

Fig. 99. Catalog Illustration of Blackhawk No. 18-AD Socket Set, 1930.

Fig. 99 shows the catalog illustration, with the tools neatly arranged in a type "A" case. The text notes that this set was "a favorite with car owners".

The customer had a choice between the double-hex sockets in set No. 18-AD for $19.15, or the slightly less expensive single-hex sockets in set No. 18-A for $18.35.

The No. 18-A set was listed in Blackhawk catalogs from 1927 through 1929, but had been discontinued in the Blackhawk catalogs by 1930.

After the above introduction, we're ready to display the No. 18-A set itself.

Fig. 100. Blackhawk No. 18-A Q.D. Socket Set, ca. 1926-1927.

Fig. 100 shows the Blackhawk No. 18-A Q.D. socket set in its original "A" style case, with the tools arranged as suggested by the catalog. (The photograph is quite detailed, so if you enlarge it, you should be able to see most model numbers and even the patent notices.)

The cover holds a No. 500 brace, and the tools in the center bay consist of a T15 crank speeder, 911X ratchet with T13 plug, T4 Tee-handle, T10 extension, T60 extension. In the upper right center are the two spark-plug sockets 130 and 136, and the two side bays hold the regular sockets: numbers 14, 16, 18, 19, 20, and 22 on the right, with 24, 25, 26, and 28 on the left. (Set No. 18-AD would be the same, except for the substitution of double-hex sockets D14-D28.)

The sturdy case has some dents and rust, and the original decal and most of the finish have been lost, but it still opens and closes easily.

The set as acquired was missing a few of the pieces, and these have been borrowed from other sets or general inventory. In particular, the T60 rotating-grip extension and two sockets (9/16 and 5/8) were from a No. 32-C set, and the T10 extension was acquired separately. Of course, it's also possible that the original owner of the set may have made replacements to the original tools.

Table 2 provides a summary of the No. 18-A[D] socket sets, based on the catalog description. Links are included to the descriptions and figures for the individual tools (when available.)

No. 22-CD/32-C Socket Wrench Set

Fig. 101. Blackhawk No. 22-CD Q.D. Wrench Set, ca. 1930.

Fig. 101 shows a mostly complete set of 1/2-drive Blackhawk Q.D. tools in an attache-like case, marked as the Q.D. Wrench Set No. 22-CD, but actually configured as set No. 32-C. The paragraphs below will explain the configuration of the very similar No. 22-C[D] and No. 32-C[D] sets.

According to the 1930 catalog MG330, the Q.D. wrench sets came in four flavors: a No. 32-CD full set, a slightly less expensive No. 22-CD "starter" set with fewer sockets and tools, and alternate versions of each with 6-point sockets instead of 12-point, sets No. 32-C and No. 22-C respectively. All of the sets were furnished with the same type "C" metal case.

The set in the photograph has an almost full complement of 6-point sockets (minus one or two lost), and so would correspond most closely to the No. 32-C model.

The discrepancy between the No. 32-C contents and No. 22-CD label has a simple and likely explanation. With four different socket set models all sharing the same model "C" case, it would have been awkward for dealers to stock all four variations of the case, differing only in the model sticker. It seems more likely that the cases would be supplied with the most popular sticker, and when a customer wanted a variant set, the tools could be adjusted from stock.

Table 3 shows the standard contents (based on catalog descriptions) for the No. 22-C/CD and No. 32-C/CD sets.

3/4-Drive Socket Tools

Blackhawk introduced larger drive sizes for its sockets and drive tools as the need for heavier-duty tools became apparent. Although the dates of introduction are somewhat uncertain, the 3/4-drive tools were probably available by 1924 but definitely by 1925, based on a catalog listing from the later year.

As far as is known, Blackhawk did not offer tools in the 5/8-drive size favored by Snap-On Wrench, its cross-town neighbor (and rival) during the 1920s.

Early "Arrowhead" [38X] 3/4-Drive 1-3/16 Hex Socket

We'll begin with an example believed to be among the earliest 3/4-drive sockets produced, still bearing the "Arrowhead" logo instead of the company name.

Fig. 102. Blackhawk Early "Arrowhead" 3/4-Drive 1-3/16 Hex Socket, ca. 1924-1925.

Fig. 102 shows a 3/4-drive Blackhawk 1-3/16 hex socket, marked "Made in U.S.A." with the Arrowhead logo. The socket is marked with the fractional size but no model number, but later would be assigned model 38X.

This socket has a cylindrical form with a band of cross-hatched knurling around the center, giving it a close resemblance to the earlier 1/2-drive sockets. In fact, when the socket is compared with the similar-sized (1-3/16 vs. 1-1/4) examples of Early 1/2-Drive Sockets shown previously, the sockets are nearly identical except for the drive sizes. This suggests that the very early 3/4-drive production was made by simply broaching a 1/2-drive socket for the larger drive size.

The use of the Arrowhead logo on this example suggests a production date as early as 1924.

Early [48X] 3/4-Drive 1-1/2 Hex Socket

Fig. 103. Blackhawk Early [48X] 3/4-Drive 1-1/2 Hex Socket, with Inset for Broaching, ca. 1925-1926.

Fig. 103 shows a 3/4-drive Blackhawk 1-1/2 hex socket, stamped "Blackhawk" and "Made in U.S.A." with the fractional size at the left. No model number was marked on this example, but the catalogs refer to this size as a model 48X socket.

Early 3/4-Drive Hex Sockets

Fig. 104. Early Blackhawk 3/4-Drive Hex Sockets, ca. 1925-1927.

Fig. 104 shows a group of several somewhat later (but still early) Blackhawk 3/4-drive hex sockets, all marked "Blackhawk Made in U.S.A." with the fractional sizes, but without model numbers.

The sizes are, from the left, 1-1/8, 1-3/16, 1-1/4, and 1-3/8. (These sockets would later be given model numbers 36X, 38X, 40X, and 44X respectively.)

With the exception of the second socket from the left, all of these sockets have a turned-down base, tapered walls, and a raised knurled band around the center.

The odd second socket is much shorter than the others and lacks the turned-down base, and also has the straight cylindrical form seen in the earlier 1/2-drive sockets. (This socket is basically identical to the previous figure except for the Blackhawk name in place of the Arrowhead logo.) As with the previous figure, the second socket was likely made by simply broaching a 1/2-drive socket for the larger drive size.

3/4-Drive yyX-Series Hex Sockets

Fig. 105. Blackhawk 3/4-Drive yyX-Series Hex Sockets, ca. 1925-1930.

Fig. 105 shows a group of 3/4-drive Blackhawk Q.D. hex sockets, each marked "Made in U.S.A." on the base.

The models and sizes are, from the left, 48X (1-1/2), 50X (1-9/16), and 52X (1-5/8).

The standard finish for these sockets was black paint, and the lefthand socket still has a few traces of paint remaining.

The sockets have a reduced base and tapered walls, and the band of cross-hatched knurling around the middle was probably intended to help with hand-turning.

50X 3/4-Drive 1-9/16 Hex Socket

Fig. 106. Blackhawk 50X 3/4-Drive 1-9/16 Socket, with Inset for Broaching, ca. 1925-1930.

Fig. 106 provides a more detailed look at one of the sockets from the above group, the Blackhawk 50X 1-9/16 hex socket.

The inset shows the interior of the socket, with some chatter marks on the walls from the cold-broached construction.

T4X 3/4-Drive Sliding Tee Handle

Fig. 107. Blackhawk T4X 3/4-Drive Sliding Tee Handle, with Inset for Marking Detail, ca. 1925-1930.

Fig. 107 shows an early 3/4-drive Blackhawk T4X sliding Tee handle, stamped "Blackhawk" and "Made in U.S.A." on the bar.

The overall length is 18.1 inches, and the diameter of the bar is 0.81 inches (13/16 nominal). The finish is plain steel.

The sliding head has an internal detent ball to help hold its position, with the hole for the ball drilled at an angle from one side, rather than in the center. The drive stud is fitted with two detent balls to provide a more secure grip.

916 3/4-Drive Ratchet with T-13X Drive Plug

Fig. 108. Blackhawk 916 3/4-Drive Ratchet and T-13X Drive Plug, with Inset for Side View, ca. 1925-1930.

Fig. 108 shows a 3/4-drive Blackhawk No. 916 ratchet fitted with the standard T-13X drive plug. The ratchet is constructed as a heavy forged body with two riveted cover plates, and the markings "Blackhawk Mfg. Co." and "Milwaukee Wis. Made in U.S.A." are forged into the flat handle.

The overall length is 15.9 inches, and the finish is plain steel.

The non-reversible ratchet mechanism has a 16-tooth drive gear and is permanently enclosed between the riveted cover plates. The T-13X drive plug is equipped with two detent balls on each side, to provide a more secure grip on the socket.

The No. 916 ratchet was listed in the 1927 Blackhawk catalog at a price of $6.50, with extra T-13X drive plugs available for $0.75. The ratchet was included as part of the No. 36B Q.D. Heavy Duty Socket Set, with the other tools consisting of a T4X sliding tee, T8X and T17X extensions, eight sockets of the series shown in the next figure, and a "B" style metal case.

916 3/4-Drive Ratchet with "DIF" Forge Mark

Fig. 109. Blackhawk 916 3/4-Drive Ratchet, with Inset for Marking Detail, ca. 1925-1930.

Fig. 109 shows another example of the 3/4-drive Blackhawk No. 916 ratchet, with a forge mark from a known merchant drop forge company. The heavy forged body is marked with "Blackhawk Mfg. Co." and "Milwaukee Wis. Made in U.S.A." forged into the flat handle, with the DIF-Square forge mark at the left, shown as a close-up in the small inset.

The overall length is 15.9 inches, and the finish is plain steel.

The DIF-Square forge mark indicates production by Interstate Drop Forge, a well-known merchant drop forge operator in Milwaukee. A later example of production for Blackhawk can be seen as the Blackhawk 69999 Ratchet.

7/8-Drive Socket Tools

Blackhawk's 7/8-drive tools were first offered in late 1925 or early 1926, based on information in the catalogs. A DuCommun Catalog from 1926 offers a full range of 7/8-drive tools, and the Blackhawk 1927 catalog, printed in 1926, implies that the 7/8-drive line had been in use for a year.

The 7/8 (square) drive size was somewhat unusual, but was also offered by Snap-On Wrench around the same time, and later by Mossberg as well.

The next several figures will show examples of Blackhawk's 7/8-drive sockets and tools.

Early 7/8-Drive 1-1/16 Hex Socket

Fig. 110. Blackhawk Early 7/8-Drive 1-1/16 Socket, with Inset for Broaching, ca. 1925-1927.

Fig. 110 shows an early 7/8-drive Blackhawk 1-1/16 6-point socket, marked "Blackhawk Made in U.S.A." with the fractional size.

This socket is not marked with a model number, but was listed as a model 34XX by the time of the 1927 catalog.

Early [52XX] 7/8-Drive 1-5/8 Hex Socket

Fig. 111. Early Blackhawk [52XX] 7/8-Drive 1-5/8 Hex Socket, with Inset for Broaching, ca. 1925-1927.

Fig. 111 shows an early 7/8-drive socket Blackhawk [52XX] 1-5/8 hex socket, stamped "Blackhawk" and "Made in U.S.A." with the fractional size.

This socket is not marked with a model number, but was listed as a model 52XX by the time of the 1927 catalog. The 1927 catalog offered 7/8-drive sockets in sizes ranging from 1-1/16 (model 34XX) up to 2-3/8 (model 76XX).

Early [70XX] 7/8-Drive 2-3/16 Hex Socket

Fig. 112. Early Blackhawk [70XX] 7/8-Drive 2-3/16 Hex Socket, with Inset for Broaching, ca. 1925-1927.

Fig. 112 shows another early 7/8-drive socket, a Blackhawk 2-3/16 6-point socket, marked "Blackhawk Made in U.S.A." with the fractional size.

This socket is not marked with a model number, but was listed as a model 70XX by the time of the 1927 catalog. The 1927 catalog offered 7/8-drive sockets in sizes ranging from 1-1/16 (model 34XX) up to 2-3/8 (model 76XX).

Early 7/8-Drive 1-7/16 Square Socket

Blackhawk also offered 7/8-drive sockets with square broachings, as illustrated in the next figure.

Fig. 113. Blackhawk Early 7/8-Drive 1-7/16 Square Socket, with Inset for Broaching, ca>. 1925-1927.

Fig. 113 shows an early 7/8-drive Blackhawk 1-7/16 square (4-point) socket, marked "Blackhawk Made in U.S.A." with the fractional size.

This socket is not marked with a model number, but was listed as a model 046XX socket in the 1927 catalog. The 1927 catalog offered 7/8-drive square sockets in nine sizes, ranging from the 1-1/16 model 034XX up to the 2 inch model 064XX.

920 7/8-Drive Ratchet

Fig. 114. Blackhawk 920 7/8-Drive Ratchet, with Insets for Side View and Marking Detail, ca. 1925-1930.

Fig. 114 shows a 7/8-drive Blackhawk 920 ratchet with a forged handle, marked with "Blackhawk Mfg. Co." and "Milwaukee, Wis. Made in U.S.A." forged into the shank.

The overall length is 20.0 inches, and the finish is black paint.

The small inset shows a forge mark resembling the overstamped letters "CSCo", visible on the shank at the right. This likely indicates the contract drop-forge operator used by Blackhawk at the time, but the company has not yet been identified. We have placed this symbol in our table of logo images as the CSCo-Logo forge mark and have listed it as an unknown forge mark in our article on Merchant Drop-Forgers.

Later versions of the Model 920 ratchet were adapted to use a Lock-on drive plug, and an example can be seen as the Later Blackhawk 920 Ratchet.

T-13XX 7/8-Drive Drive Plug

Fig. 115. Blackhawk T-13XX 7/8-Drive Drive Plug, with Inset for End View, ca. 1925-1930.

Fig. 115 shows the 7/8-drive Blackhawk T-13XX drive plug for use with the 920 ratchet in the previous figure. The plug is stamped with the model number on the side, but no other markings are legible.

The overall length is 2.2 inches, and the finish is plain steel.

T-8XX 7/8-Drive Tee-Head Extension

Fig. 116. Blackhawk T-8XX 7/8-Drive Tee-Head Extension, with Insets for Construction and Marking Detail, ca. 1925-1932.

Fig. 116 shows a 7/8-drive Blackhawk T-8XX extension and sliding Tee head, stamped "Made in U.S.A." on the drive head.

The overall length is 9.2 inches, and the finish is black paint.

The extension is designed to work as a sliding Tee head using the Blackhawk T-4XX cross-bar, a 24 inch bar with a 1 inch diameter. The top inset shows the cross-bar hole, equipped with a detent ball to help secure the bar.

Other Q.D. Drive Sizes

The Blackhawk Q.D. line also included tools in the smaller 3/8-drive and 1/4-drive sizes, although these other sizes are less frequently found.

With the advent of the Lock-On line in the late 1920s, 1/4-drive tools were given the same improved surface polish and chrome-plated finish as the Lock-On tools, even though they continued to use friction balls in the drive studs. Since the 1/4-drive tools resembled the Lock-On line in appearance, these models are shown in a Later Section.

Blackhawk 8xx Series 3/8-Drive Q.D. Sockets

Fig. 117. Blackhawk 12-point 3/8-Drive Q.D. Sockets, From Left: 814, 816.

Fig. 117 shows two 12-point 3/8-drive Blackhawk sockets of the 8xx series, marked "Made in U.S.A." and with some of the original black paint remaining. In the 8xx series the "xx" number is the size in 32nds, so the models and sizes in the photograph are (from the left) 814 (7/16) and 816 (1/2). The sockets have a knurled band similar to that on the larger drive sizes.

The 1930 catalog MG-330 offered the 8xx series sockets in sizes 5/16, 3/8, 7/16, 1/2, 9/16, and 5/8.

That completes our discussion of the Q.D. sockets and drive tools. In the next sections we'll first look at Blackhawk's early open-end and box-end wrenches, then proceed to the Lock-On tools, one of Blackhawk's most notable developments and the successor to the Q.D. series.