Alloy Artifacts

The Development of Lock-On Sockets

In the late 1920s Blackhawk worked intently on developing new methods for securing sockets to their drive tools. Their progress can be traced through a somewhat confusing series of overlapping patents filed around this time, and ultimately resulted in the "Lock-On" line of tools with locking studs and release buttons. To trace the development of the Lock-On products, it's helpful to look at the filing dates for the relevant patents, as several important patents were issued out of order with their filing.

• The earliest related patent was #1,685,503, filed in 1927 and issued in 1928. It described a threaded locking stud that could be manually retracted when only a friction-ball coupling was needed.

• Patent #1,896,645, the key patent for the Lock-On concept, was filed in 1929 but not issued until 1933. It describes a spring-loaded locking pin installed in the drive tools, together with a release button fitted in the sockets. Due to some technical problem, this patent was reissued in 1934 as patent #RE19,287, and this later patent number will be seen marked on many tools.

• Patent #1,807,134 was filed in 1930 and describes a socket wrench drive plug fitted with two spring-loaded pins. This was intended as an improved push-through drive plug for female-drive ratchets, as the two pins retained the plug securely, but allowed it to be replaced easily if needed.

• Patent #1,927,844 was filed on Jan. 27, 1932 and completed the important Lock-On patents. The key concept here was to place the locking pin at an angle, so that the pin could be automatically depressed by a socket pushed onto the drive stud. By avoiding the need to manually depress the lock pin, Lock-On tools became much more convenient to use, on par with the conventional friction-ball tools.

• Patent #1,982,008 was filed on Feb. 23, 1934 and issued late that year, and offers a minor refinement to the Lock-On design. The patent describes the optimal Lock-On hole size in order to hold the socket tightly, and may be found marked on some of the sockets produced in the mid to late 1930s.

• Patent #2,190,081, the last of the Lock-On patents, was filed in 1938 and issued in 1940. It describes an insertable sleeve used to retain the release button, as an alternative to crimping the outer opening. This was needed especially for sockets in the smaller sizes, as the thin walls of the drive end didn't have enough material to allow movement of the release button.

The series of patents show that the Lock-On ideas were developed in stages, and the corresponding products were offered in stages as well. The trademark records cite June 30, 1930 as the first commercial offering of Lock-On tools, and the 1930 catalog MG330 provides a snapshot of the products at this time. It shows the Lock-On tools with a spring-loaded pin, but the sockets do not yet have a release button; instead, the sockets have a hole to receive the pin, but a separate tool (a simple offset pin) was required to release the lock.

For some period of time Blackhawk sold both the conventional friction-ball tools (the "Quick Disconnect" or Q.D. line) as well as their new Lock-On tools, which were christened the "Chief" line. (Of course, the new Lock-On tools could have been called the "Slow Disconnect" line, but that didn't have the same marketing ring to it.) The Chief tools were apparently intended as a high-end or premium line and featured a polished chrome finish.

The 1930 catalog MG330 shows that both Q.D. and Chief product lines were available at that time, and Lock-On tools were offered in drive sizes 3/8, 1/2, and 3/4. (The 3/8-drive tools were in full sets only.) But once the socket release buttons and slanted locking pins were fully developed, Blackhawk made the bold (and risky) move of dropping their friction-ball tools, except for the smallest drive sizes where locking studs were impractical.

In the discussion that follows, we'll begin with the 1/2-drive Lock-On sockets, then examine the corresponding 1/2-drive tools. The other drive sizes will then be shown in later sections, as the development of these tools basically parallels the 1/2-drive case.

1/2-Drive Lock-On Sockets

The next few figures here will show some of the earliest examples of Lock-On sockets, tools that were produced before the first Lock-On patent was issued. These sockets all have a "Pat. Pend." notation, and the known dates of the patent filing allow a reasonable estimate of the production date. Since the key #1,896,645 patent hadn't been issued yet, the expected manufacturing date would fall within the range 1929-1933.

This estimated interval can be narrowed for certain model series, based on additional information about the sockets. Blackhawk catalogs for 1929 and 1930 show that the Lock-On tools were offered in stages, with only limited models available in 1929, significantly expanded offerings by early 1930, and still other models offered later.

The early Lock-On sockets did not include release buttons, even though the patent description shows sockets fitted with buttons. Instead, a small tool with a pin was needed to release the sockets from the drive stud.

Since release buttons were an important convenience feature, Blackhawk undoubtedly wanted to offer these as soon as possible, but apparently the manufacturing details took some time to resolve. As late as 1934 the Blackhawk catalog shows release buttons only on the larger 7/8-drive sockets, and presumably the smaller drive sizes were fitted in late 1934 or 1935.

Since the main Lock-On patents had been issued by 1933 (and the re-issue patent in 1934), and release buttons arrived in 1934 or later, we would expect to see the Lock-On patents marked on any socket with a release button. (Except perhaps for the 7/8-drive sockets, but these are rarely seen anyway.) Conversely, any socket with the Lock-On patents pending should not have a release button. (Earlier editions of this article had suggested that release buttons could have arrived by early 1932, but this is apparently not the case.)

Early 84xx Series 1/2-Drive 12-Point Sockets

We'll start the socket presentation with some of the earliest examples available, two 1/2-drive sockets in the 12-point 84xx series. Fig. 131 shows a Blackhawk model 8421 21/32 socket on the left, with a model 8424 3/4 socket on the right. Both are marked "U.S.A." and "Pat. Pend." but with no patent numbers, an indication of their early manufacturing date.

Fig. 131. Blackhawk 1/2-Drive 84xx Sockets, with Inset for Drive Ends, ca. 1929-1933.

The sockets have a hole for the locking pin, but were not fitted with release buttons, as apparently the manufacturing details hadn't been worked out yet. The socket design includes a thin knurled band, providing continuity with the prior designs but mostly decorative in nature. The finish is polished chrome.

The 84xx sockets featured tapered walls and were the direct successors of the Dxx sockets in the Q.D. line; refer to an example of the Dxx sockets for comparison. The 84xx series was among the first group of Lock-On tools offered, and are listed in a 1929 Blackhawk Mechanic's Guide. The patent pending marking leads to an estimated manufacturing date in the range 1929-1933.

The inset in the photograph shows an important detail, the scalloped indentations machined into the drive ends. These indentations were intended to help depress the locking pin when attaching the socket to a drive stud, a convenience feature when using Lock-On tools. Such indentations would not have been needed once the slanted locking pins of patent #1,927,844 were in use, but even after switching to the slanted pins, the indentations in the sockets provided backwards compatibility for owners of the older drive tools.

Early 8432 1/2-Drive 12-Point Socket

Fig. 132. Blackhawk 1/2-Drive 8432 Socket, with Insets for Drive End and Broaching, ca. 1929-1933.

Fig. 132 shows another early example of the 84xx series in greater detail, a Blackhawk model 8432 socket marked "Pat. Pend." on the base.

This example has the tapered walls and knurled band seen in the previous figure, but as a larger-sized socket has a reduced base.

The left inset shows the drive end with the scalloped indentations discussed in the previous figure. The hole for the locking pin appears at the front of the socket.

8928 1/2-Drive Deep Socket

Fig. 133. Blackhawk Early 1/2-Drive 8928 Deep Socket, ca. 1930-1933.

Fig. 133 shows another early Lock-On socket, a 1/2-drive model 8928 7/8 deep socket with a cross-bar hole. The socket is marked "U.S.A." with "Pat. Pend.", again indicating an early manufacturing date. Another marking states "Use for Spark Plugs Only", providing the intended application.

The drive end of the socket includes the scalloped indentations discussed with the previous example, to assist with inserting the drive stud. The socket also includes a thin knurled band around the base, a decorative feature providing continuity with earlier designs.

This socket includes a cross-bar hole, a common feature for spark-plug sockets at the time. The cross-bar holes apparently served double-duty for the Lock-On pin as well, as there is no separate hole for the pin. (And obviously, no release button either.)

The model 8928 socket was not yet listed in the 1930 MG330 catalog, so the patent pending status suggests that a manufacturing date of late 1930 to 1933 is probably reasonable.

Early 66xx Series 1/2-Drive Sockets

Fig. 134. Blackhawk Early 1/2-Drive 66xx Series Sockets, with Inset for Drive Ends, ca. 1930-1933.

Fig. 134 shows several examples of early Lock-On sockets in the 1/2-drive 66xx series, which featured thin straight walls and 12-point broachings. The sockets are all marked "U.S.A." and "Pat. Pend.", but with no patent numbers, indicating an early manufacturing date.

The model numbers and sizes are, from the left, model 6614 (7/16), 6625 (25/32), and 6626 (13/16).

These sockets have a hole for the locking pin, but were not fitted with release buttons. The socket design includes a thin knurled band, mostly decorative in nature, and likely a carry-over from the earlier functional knurling used for gripping the socket.

The 66xx series sockets are not listed in the MG330 catalog of 1930. Together with the patent pending status, this leads to an estimated manufacturing date in the range of late 1930 to 1933.

The inset to the photograph shows the drive ends with scalloped indentations, a feature intended to help depress the locking pin, as was discussed above. Blackhawk sockets retained these indentations through the life of the 66xx series and into the early successor 401xx series, as the later figures below will show. The presence of the indentations will assist in identifying early examples of the later socket series, as will be seen shortly.

Later 8432 1/2-Drive 12-Point Socket

Fig. 135. Blackhawk 1/2-Drive Model 8432 1 Inch Socket, with Inset for Drive End, ca. 1934-1938.

In Fig. 135 we see a later 1/2-drive socket in the 84xx series, the Blackhawk model 8432 1 inch socket. The socket is marked "Made in U.S.A." with patents "U.S. Pat's 1,927,844 RE.19,287 1,982,008".

This socket is comparable to the earlier 84xx sockets shown above. The finish is polished chrome, and the socket design includes the thin knurled band seen in the previous figures.

A few comments are in order regarding the patent numbers, as this is our first socket example to be marked with these patents. The re-issue patent #RE19,287 refers to the same claims as patent #1,896,645, the key Lock-On patent, and corrected some technical problem in the original filing. Although about a year elapsed between the issue of patents #1,896,645 and #RE19,287, no tools have been found marked with the former number.

The patent #1,927,844 defined the use of a slanting drive stud and so, strictly speaking, shouldn't apply to sockets; however, Blackhawk always listed patents #1,927,844 and #RE19,287 together. Finally, the patent #1,982,008 noted here seems to have been marked only for a limited time, on sockets from the mid to late 1930s.

Later 66xx Series 1/2-Drive Sockets

Fig. 136. Blackhawk 1/2-Drive 66xx Series Sockets, with Inset for Drive Ends, ca. 1934-1937.

Fig. 136 shows another group of the 1/2-drive 66xx series Lock-On sockets, but produced at a later date, after the patent numbers were available. The sockets are marked "Made in U.S.A." with "U.S. Pats. 1927844 RE19287 1982008"; note the presence of the #1,982,008 patent, issued in late 1934.

The models and sizes are, from the left, 6621 (21/32), 6628 (7/8), and 6630 (15/16). The inset shows the drive end indentations, similar to the previous figure.

The patent number markings on these sockets place the date of manufacture some time after late 1934. At this time all Lock-On sockets were being fitted with release buttons, as shown in the figure. (The lefthand socket has lost its button.)

Around 1938 or so, Blackhawk phased out the 66xx series sockets in favor of the 401xx series, a line with basically the same specifications but a slightly different design.

8124 1/2-Drive 8-Point Socket

Fig. 137. Blackhawk 8124 1/2-Drive 3/4 8-Point Socket, ca. 1934-1938.

Fig. 137 shows another 1/2-drive Lock-On socket from the 81xx 8-point series, the Blackhawk model 8124 3/4 socket. The socket is marked "U.S. Pats. RE19287 1,927,844", the usual Lock-On patents, but also shows patent #1,982,008.

This socket also has the thin knurled band as seen in the previous figures.

The Three-Groove Socket Design

The sockets shown up to this point have included a cross-hatched or knurled band, a stylistic hold-over from the days when a band of coarse knurling served as a hand grip. In 1937 Blackhawk decided it was time for a makeover in socket style, and Sigmund Mandl developed a new socket design with three grooves around the base. Mandl filed a design patent for this three-groove socket style, and the patent was issued in 1938 as #D108,143.

The three-groove design went into production in late 1937 or early 1938, and Blackhawk used this style for all of their sockets, except for the 1 inch drive size.

Around this same time Mandl also filed a design patent for a tool handle with raised ribs, apparently as a "coordinating style" for the sockets, and examples of this "Gripline" handle style will be seen later.

Early 401xx Series 1/2-Drive 12-Point Sockets

Fig. 138 shows several of the 401xx series 1/2-drive 12-point Lock-On sockets, the successors to the 66xx models. As will be explained in the text below, these appear to be early examples of the 401xx series. The model numbers and sizes are, from the left, 40112 (3/8), 40136 (1-1/8), and 4140 (1-1/4). All are marked "Made in U.S.A." and "U.S. Pats. 1,927,844 RE19,287", except that that rightmost socket is missing the patent markings.

Fig. 138. Blackhawk 401xx 1/2-Drive Lock-On Sockets, with Inset for Drive Ends, ca. 1937-1938.

There are several details to be noted that collectively suggest that these are very early examples of the 401xx socket series. The first is the presence of the scalloped indentations in the drive ends, as shown in the inset. This was a feature we saw in 66xx series sockets that is absent from most examples of the 401xx series. Most 401xx sockets show only a small chamfer at the drive end, as this was found to be sufficient for operation with the improved Lock-On drive studs.

Another detail is the large font size for the stamped model numbers; compare these to the other figures for 401xx series sockets. The rightmost socket also shows yet another marking oddity: the model number has been stamped incorrectly, as "4140" instead of "40140". This suggests that perhaps the marking machinery was still being set up for the 401xx models, or possibly they were being stamped by hand.

The last detail to note is that these sockets have no date code marked, a notable absence since most sockets of this style do show a date code.

If the above reasoning has established that these are early examples of the 401xx series, the likely date of manufacture can be determined by a patent reference. The Blackhawk design patent for the three-groove socket design has been described above, and the patent #D108,143 was filed in early 1937 and issued in 1938. It's reasonable to assume that production of the sockets would have begun around the same time, making it likely that these sockets were manufactured in 1937 to early 1938. (Date codes are known to have been marked on sockets by sometime in 1938.)

40134 1/2-Drive 12-Point Socket

Fig. 139. Blackhawk 40134 1/2-Drive Lock-On Socket, with Inset for Drive End, 1939.

In Fig. 139 we see a single 1/2-drive Blackhawk model 40134 1-1/16 Lock-On socket, marked "Made in U.S.A." and "U.S. Pats. 1927844 RE19287".

The inset shows the drive end indentations, indicating that this is another fairly early example of the 401xx series. However, unlike the previous examples, this one is marked with a date code of "9", visible in the photograph to the right of "Blackhawk".

The presence of both the indentations and date code is significant, as it means that the manufacturing date would have been 1939, and the date code system must have started in the late 1930s. This socket was very helpful in refining the interpretation of the date codes.

Later 401xx Series 1/2-Drive 12-Point Sockets

Fig. 140. Blackhawk 1/2-Drive 401xx Lock-On Sockets, from Left: 8124, 40119, 40120, 40132.

Fig. 140 shows a group of later Lock-On sockets with the older model 8124 socket included for comparison. All are 1/2-drive with model numbers (from the left) 8124 (3/4, 8pt), 40119 (19/32, 12pt), 40120 (5/8, 12pt), and 40132 (1", 12pt). All are marked "U.S. Pats. RE19287 1,927,844".

Note that the middle two sockets are finished with a thin (and worn) cadmium plating, and these two sockets both have a date code of "4". The righthand socket is chrome plated and has a date code of "1". (The socket on the left is also chrome plated, but is an older model with no date code.) These details contributed to understanding the date code system explained earlier.

403xx Series 1/2-Drive 12-Point Deep Sockets

Fig. 141. Blackhawk 1/2-Drive Deep Lock-On Sockets, from Bottom: 40316, 40320.

Fig. 141 shows two 1/2-drive deep 12-point Lock-On sockets, both marked "U.S. Pats. 1927844 RE19287". The models and sizes are (from the bottom) 40316 (1/2) and 40320 (5/8).

The bottom socket is marked with a date code of "4" and has a cadmium finish, which is consistent with manufacture in 1944. The top socket is marked with a date code of "1" and is finished in polished chrome, consistent with manufacture in 1941.

The sockets have a hole for a cross-bar, a common feature for deep sockets at the time.

40332 1/2-Drive 1 Inch Deep Socket

Fig. 142. Blackhawk 40332 1/2-Drive 1 Inch Socket, with Insets for Broaching and Marking Detail, 1946.

Fig. 142 shows a another example of the 403xx series, a 1/2-drive Blackhawk 40332 1 inch deep socket. The base is stamped "Made in U.S.A." with a "-6" date code, and a "U.S. Pat's. 1927844 RE.19,287" patent notice appears part way up the socket wall.

The lower inset shows the broaching and construction details. Note that the inside has a stepped diameter to provide clearance and reduce the weight.

1/2-Drive Lock-On Tools

We've now seen a number of examples of the Lock-On sockets, so it's time to look at the corresponding drive tools. We'll begin with several early examples fitted with the original (non-slanted) Lock-On pins, and marked with a "Pat. Pend." notation. These tools were produced while the Lock-On designs were still being developed, and have a manufacturing date in the range 1929-1932.

Early 9204 1/2-Drive Sliding Tee Handle

Fig. 143A. Blackhawk 9204 1/2-Drive Sliding Tee Handle, with Inset for Marking Detail, ca. 1929-1932.

Fig. 143A shows a rare 1/2-drive Blackhawk 9204 sliding Tee handle, stamped "Pat. Pend." and "U.S.A." on the bar.

The overall length is 11.0 inches, and the finish is chrome plating.

The patent pending notation refers to patent #1,896,645, and based on the patent filing date, this tool was likely made in 1929-1932.

The Model 9204 sliding Tee was among the first Lock-On tools offered by Blackhawk, and this model is listed in the 1929 Blackhawk Mechanic's Guide catalog.

Early 9210 1/2-Drive Swivel-Grip Extension

Fig. 143B. Blackhawk 9210 1/2-Drive Extension, ca. 1929-1932.

Fig. 143B shows a Blackhawk model 9210 rotating-grip extension, marked with a "Pat. Pend." notation.

The overall length is 10.0 inches.

As this is a first-generation Lock-On tool with a non-slanted locking pin, the patent pending notation refers to patent #1,896,645. Based on the patent filing date, this tool was likely made in 1929-1932.

The Model 9210 extension is listed in the 1929 Blackhawk Mechanic's Guide catalog, making it among the first Lock-On tools offered. Note that the rotating grip has a knurled surface, the handle style used from the late 1920s until sometime in the 1930s.

Early 9506 1/2-Drive Brace

Fig. 144. Blackhawk 1/2-Drive 9506 Brace, with Insets for Detail, ca. 1929-1932.

Fig. 144 shows a 1/2-drive Blackhawk model 9506 brace or speeder, marked with a "Pat. Pend." notation.

The brace has a throw of 4.7 inches and an overall length of 16.2 inches.

The brace is equipped with a rotating knurled hand grip as well as a knurled end piece. The finish is a thin chrome plating, now worn through in some areas.

Early 9611 1/2-Drive Speeder

Fig. 145. Blackhawk 9611 1/2-Drive Speeder, with Inset for Detail, ca. 1929-1932.

Fig. 145 shows a 1/2-drive Blackhawk model 9611 speeder, marked with a "Pat. Pend." notation. The speeder has a throw of 4.7 inches and an overall length of 19.4 inches.

The model 9611 speeder was among the first Lock-On tools and is listed in the 1929 Blackhawk Mechanic's Guide catalog.

The knob on this tool is a replacement for the original, though rather nicely done with polished wood (walnut) for the end. The original knob was a patented design described by patent #1,764,690, and an example can be seen in a later figure for the 49994 speeder. (The 1929 catalog promised the knob to be "practically indestructible".)

Early 9802 1/2-Drive Drive Plug

Fig. 146. Blackhawk 9802 1/2-Drive Drive Plug, ca. 1930-1931.

Fig. 146 shows a 1/2-drive Blackhawk 9802 drive plug, marked "U.S.A." with a "Pat. Pend." notation. The overall length is 1.4 inches.

The pending status here refers to patent #1,807,134, filed by E.M. Pfauser in 1930 and issued in 1931. The two locking pins are used to keep the drive plug captive in the ratchet drive gear, while also allowing for an easy replacement in the case of breakage. Note that the locking pins are also backed by conventional detent balls, perhaps for a better holding grip.

9811 1/2-Drive Ratchet

Fig. 147. Blackhawk 9811 1/2-Drive Ratchet, with Inset for Side View, ca. 1929-1932.

Fig. 147 shows a 1/2-drive Blackhawk 9811 ratchet, stamped "Made in U.S.A." in the recessed panel of the handle.

The overall length is 10.0 inches, and the finish is plain steel.

The 9811 ratchet was intended for use with the 9802 drive plug shown in the previous figure. The drive gear of the ratchet includes a groove to engage the locking pins of the plug, visible in the photograph at the left. A barrier in the center of the groove prevents the plug from being pushed all the way through.

The 9811 ratchet was among the first Lock-On tools offered in 1929, and was essentially the same as the earlier Q.D. Model 911X Ratchet, but with a modified drive gear to use the 9802 Lock-On drive plug. This example has a 14-tooth drive gear, a relatively coarse mechanism used in the earlier models.

By 1934 the 9811 ratchet was being offered with a reversing lever, and was later superseded by the Model 49977 Ratchet shown later in this article.

Early 8502 1/2-Drive Universal

Fig. 148. Blackhawk 1/2-Drive 8502 1/2-Drive Universal, ca. 1929-1932.

Fig. 148 shows an early 1/2-drive Blackhawk model 8502 universal, marked "U.S.A." with a "Pat. Pend." notation. The overall length is 2.8 inches.

The finish is polished chrome, although worn through in many areas. The markings on this tool were too faint to show well in the photograph, as the surface is worn apparently from rolling around in a toolbox.

The 8502 universal was among the first Lock-On tools offered, and is listed in the 1929 Blackhawk Mechanic's Guide catalog. This tool is fitted with the original Lock-On drive stud, perpendicular to the surface rather than slanted. To assist with inserting the drive studs, early Lock-On sockets (and drive tools) were made with indentations in the drive end, to help depress the locking pin.

Early 9202 1/2-Drive Offset Breaker Bar

Fig. 149. Blackhawk 9202 1/2-Drive Offset Breaker Bar, ca. 1930-1932.

Fig. 149 shows a rare 1/2-drive Blackhawk 9202 breaker bar with a distinctive offset head, marked "Made in U.S.A." with a "Pat. Pend." notice.

The overall length is 11.1 inches. The original finish was chrome plating, but most of the finish has been lost to wear and rust.

This is a first-generation Lock-On tool with a non-slanted locking pin, and the patent pending notice refers to patent #1,896,645.

The 9202 breaker bar was not listed in the 1929 Blackhawk Mechanic's Guide, but was offered in the 1930 MG330 catalog. Based on the patent date and catalog information, this tool was likely made in 1930-1932.

Early 9207 1/2-Drive Flex-Head Breaker Bar

Fig. 150. Blackhawk 9207 1/2-Drive Flex-Head Breaker Bar, ca. 1930-1932.

Fig. 150 shows a 1/2-drive Blackhawk 9207 flex-head breaker bar, marked "Made in U.S.A." with a "Pat. Pend." notice. The knurled handle has a cross-bar hole with a detent ball, allowing for convenient usage as a Tee handle.

The overall length is 11.7 inches, and the finish is chrome plate.

The model 9207 breaker bar was not listed in the 1929 Blackhawk Mechanic's Guide, but was included in their 1930 MG330 catalog, where it is referred to as a "Hinged Offset Handle". As a first-generation Lock-On tool with a non-slanted locking pin, the patent pending notice refers to patent #1,896,645. Based on the patent date and catalog information, this tool was likely made in 1930-1932.

Early 9208 1/2-Drive Flex-Head Breaker Bar

Fig. 151. Blackhawk 9208 1/2-Drive Flex-Head Breaker Bar, with Insets for Marking and Construction Detail, ca. 1930-1932.

Fig. 151 shows a similar but longer flex handle, the 1/2-drive Blackhawk 9208 flex-head breaker bar. The shank is stamped "Made in U.S.A." with a "Pat. Pend." notice, and the knurled handle has a cross-bar hole with a detent ball (see insets).

The overall length is 15.7 inches. The original finish was chrome plating, but virtually all of the plating has been lost due to extensive wear.

As with the previous figure, this model was not listed in the 1929 Blackhawk Mechanic's Guide, but was included in their 1930 MG330 catalog. The patent pending notice refers to patent #1,896,645, which together with the catalog information indicates production in the range 1930-1932.

That completes our look at the Lock-On tools produced before the basic patents were issued. For the remainder of this section, we'll look at examples marked with the Lock-On patents.

9206 1/2-Drive 6 Inch Rotating-Grip Extension

Fig. 152. Blackhawk 9206 1/2-Drive 6 Inch Rotating-Grip Extension, with Insets for Construction and Marking Detail, ca. 1934-1936.

Fig. 152 shows a rare 1/2-drive Blackhawk 9206 6 inch extension with a knurled rotating grip, stamped "Blackhawk" and "Made in U.S.A." with a "U.S. Pats. 1,927,844 RE.19,287 1,982,008" patent notice.

The overall length is 6.0 inches, and the finish is chrome plating with losses due to wear.

The upper right inset shows the construction details of the drive end. Note that the cross-bar hole is fitted with a detent ball to help secure the bar when in use, a convenience feature sometimes missing from modern tools. Note also that the drive opening has indentations on all four sides, a convenience when using older tools without the slanted locking pin.

The Model 9206 rotating-grip extension was among the first Lock-On tools offered by Blackhawk, and this model is listed in the 1929 Blackhawk Mechanic's Guide catalog. This particular tool dates from a few years later though, as the patent markings indicate production in 1934 or later.

49983 1/2-Drive 6 Inch Rotating-Grip Extensions

The next several figures will show examples of the Blackhawk 49983 extension, a popular tool with a rotating hand grip. We're fortunate to have acquired examples spanning a range of date codes and handle styles.

Fig. 153A. Blackhawk 49983 1/2-Drive 6 Inch Extension with Rotating Grip, ca. 1937-1938.

Fig. 153A shows an early Blackhawk model 49983 1/2-drive 6 inch extension with a rotating grip, marked "Made in U.S.A." with the "U.S. Pats. 1,927,844 RE19,287" patent notice.

The overall length is 6.0 inches, and the finish is polished chrome.

The cross-bar hole has a detent ball to help secure the bar when in use, a convenience feature missing from modern tools.

The rotating hand grip on this tool has distinctive raised ribs along the axis, a style called "Gripline" in the Blackhawk catalogs. The Gripline style was based on the design patent #D108,159, filed by Sigmund Mandl in 1937 and issued in 1938. Blackhawk used the Gripline style from about 1938 through 1946, and we'll see numerous other examples of these handles in the figures that follow.

No date code was marked on this tool, but several details will help to estimate the manufacturing date. The Gripline handle indicates production in 1938 (or late 1937) or later, based on the filing of the design patent. In addition, the drive end of the extension has scalloped indentations, a feature seen in the earlier 401xx series sockets. Finally, the absence of a date code itself may indicate that the tool was made before the start of the coding system. From these considerations, this extension was likely made in late 1937 or early 1938.

Fig. 153B. Blackhawk 49983 1/2-Drive 6 Inch Extension with Rotating Grip, 1943.

Fig. 153B shows a somewhat later example of the model 49983 extension, marked "Made in U.S.A." with a "-3" date code, and with the usual "U.S. Pats. RE19287 1,927,844" patent notice.

The overall length is 5.9 inches, and the finish is cadmium plating.

The rotating grip is in the Gripline style we saw in the previous example. The Gripline handle and "-3" date code on the tool indicate a manufacturing date of 1943, which is consistent with the wartime manufacturing date suggested by the cadmium finish.

Fig. 154. Blackhawk 49983 1/2-Drive 6 Inch Extension with Rotating Grip, with Insets for Drive End and Marking Detail, 1947.

In 1947 Blackhawk changed its tool handles to a style with circular grooves instead of longitudinal ribs. An example of this later handle style is shown in Fig. 154, a model 49983 extension marked "Made in U.S.A." with a "7" date code, and with a "U.S. Pat's. 1927844 RE19287" patent notice. (The markings are very faint due to wear.)

The overall length is 5.5 inches, somewhat shorter than the earlier models above. The finish is chrome plating with losses due to wear.

The "7" date code with the updated handle style indicates a manufacturing date of 1947.

The left inset shows the cross-bar hole and detent ball in the drive end, making this tool highly functional as a T-handle.

49987 1/2-Drive 10 Inch Extension with Rotating Grip

Fig. 155. Blackhawk 49987 1/2-Drive Swivel-Grip Lock-On Extension, 1941.

Fig. 155 shows a longer model 49987 1/2-drive swivel grip extension, marked "Made in U.S.A." and "U.S. Pats. 1927844 RE19287".

The overall length is 10.0 inches, and the finish is polished chrome.

The rotating grip is the Gripline style seen in some of the previous examples. The date code is marked "-1", which together with the Gripline style indicates a manufacturing date of 1941.

49978 1/2-Drive Universal

Fig. 156. Blackhawk 49978 1/2-Drive Universal, 1941.

Fig. 156 shows a Blackhawk model 49978 universal, marked "Made in U.S.A." with "U.S. Pats. 1,927,844 RE19287".

The overall length is 2.6 inches.

The date code is marked "1" to indicate production in 1941. An additional code "FR" follows the date code digit, but the meaning of this marking is currently unknown.

The slanted locking pin of patent #1,927,844 can be seen clearly in this figure.

49985 1/2-Drive Flex-Head Breaker Bar

Fig. 157. Blackhawk 49985 1/2-Drive Flex-Head Breaker Bar, with Inset for Detail, 1941.

Fig. 157 shows a Blackhawk model 49985 1/2-drive flex-head breaker bar, marked "Made in U.S.A." with "U.S. Pats. RE19287 1927844".

The overall length is 19.6 inches.

The handle is the "Gripline" style with parallel ribs, and has a cross-bar hole for use as a T-handle. In addition, the handle end has been drilled out for an extension bar.

The breaker bar is marked with a date code of "-1", which together with the handle style indicates production in 1941.

49994 1/2-Drive Speeder

Fig. 158. Blackhawk 49994 1/2-Drive Speeder, with Inset for Marking Detail, 1941.

Fig. 158 shows a Blackhawk model 49994 1/2-drive speeder, marked "Made in U.S.A." with a "U.S. Pats. RE19,287 1,927,844" patent notice. The wide circular end-piece is also marked "U.S. Pats. 1,764,690" for the patent on the end-piece construction.

The overall length is 15.7 inches, and the finish is chrome plating.

The speeder is marked with a date code of "-1", indicating production in 1941 or 1951.

49977 1/2-Drive Ratchet

Fig. 159. Blackhawk 49977 1/2-Drive Ratchet, with Insets for Side View and Marking Detail.

Fig. 159 shows a Blackhawk 49977 1/2-drive ratchet with a stamped steel body, marked "Made in U.S.A." with "U.S. Pats. 1927844 RE.19287" on the reverse.

The overall length is 10.0 inches, and the finish is plain steel.

The ratchet is marked with a "9" date code, which could indicate production in either 1939 or 1949. The reverse side has an "FR" code of currently unknown meaning.

The 49977 ratchet is the successor to the Model 9811 and Q.D. Model 911X ratchets, and is in fact nearly identical to the later versions of the older models. The ratchet mechanism uses an 18-tooth main gear and is fitted with a Lock-On drive stud.

49997 1/2-Drive Gearless Ratchet

One of the Blackhawk's notable innovations in drive tools was their development of practical and effective gearless ratchets, which they termed "Free-Wheeling" ratchets. The gearless designs were developed and patented beginning in 1931 with patent #1,936,640 (issued in 1933), and later with patent #2,003,155, issued in 1935.

Fig. 160. Blackhawk 49997 1/2-Drive Free-Wheeling Ratchet, with Insets for Detail, 1938.

Fig. 160 shows a Blackhawk model 49997 1/2-drive gearless ratchet, with the markings "Made in U.S.A.", "Free-Wheeling Ratchet", and "U.S. Pats. RE19287 1927844 1936640 2003155".

The overall length is 10.8 inches. The finish of the ratchet is polished chrome, and the handle design is the "Gripline" style previously seen on several extensions, a style known to have been in use by 1941 or earlier.

The left hand inset shows the date code of "-8", which together with the handle style indicates production in 1938. This is the (currently) our earliest date-coded example of the Gripline handle style.

49997 1/2-Drive Gearless Ratchet

Fig. 161. Blackhawk 49997 1/2-Drive Free-Wheeling Ratchet, with Insets for Detail, 1942.

Fig. 161 shows another Blackhawk model 49997 1/2-drive gearless ratchet, stamped "Made in U.S.A." with a "-2" date code, and with the patents "U.S. Pats. RE19287 1927844 1936640 2003155". The ratchet is also marked "Free-Wheeling Ratchet" and "Trade Mark Reg.", although no trademark registration has been found.

The overall length is 10.8 inches, and the finish is cadmium plating.

The handle design is the "Gripline" style previously seen on several extensions, and this style is known to have been in use by 1938. The Gripline handle and "-2" date code indicate a manufacturing date of 1942, which is consistent with wartime production suggested by the cadmium finish.

49973 1/2-Drive Ratchet Adapter

Fig. 162. Blackhawk 49973 1/2-Drive Ratchet Adapter, 1942.

Fig. 162 shows a Blackhawk model 49973 1/2-drive ratchet adapter, marked "Made in U.S.A." with "U.S. Pats. RE19287 1927844 1995009 2286917". The overall length is 2.4 inches.

The ratchet adapter is finished in polished chrome, and is marked with a date code of "-2", consistent with production in 1942.

Of the four patents marked on the tool, patent #1,995,009 covers the design of the basic ratchet mechanism. The key innovation here was to place the ratchet gear in the body and let the pawl assembly rotate with the drive stud. This gave the gear a larger circumference and allowed more teeth for a finer action.

One detail to note here is the relatively small diameter for a 1/2-drive ratchet adapter, measured at only 1.18 inches. The 1941 catalog HG41 has a table of specifications for the ratchet adapters, and it lists the diameter for model 49973 as 1-3/16 inches. (The same diameter as the 7/16-drive model.)

However, the later catalog No. 247 of 1947 gives the diameter of the model 49973 adapter as 1-5/16 inches at that time, and a 1953 Blackhawk catalog confirms the continued use of the 1-5/16 diameter. The figure below will show an example of a later model with the larger diameter.

Later 49973 1/2-Drive Ratchet Adapter

Fig. 163. Blackhawk 49973 1/2-Drive Ratchet Adapter, 1952.

In Fig. 163 we see another model 49973 ratchet adapter, marked as above with "Made in U.S.A." and "U.S. Pats. RE19287 1927844 1995009 2286917". The overall length is 2.5 inches.

This adapter is very similar to the one in the previous figure, but the body has a larger diameter of 1-5/16 inches. The date code is marked as a "2", but as this adapter has the larger diameter specified in 1947 and later, the date code indicates a production date of 1952. This tool was helpful in confirming the extension of the date code system beyond 1947.

This unit was disassembled for cleaning and lubrication, and the ratchet mechanism was noted as using two pawls in a symmetrical arrangement. The earlier model has not yet been disassembled for comparison, but it may be that the increased body diameter was needed to allow the use of the stronger dual-pawl design.

49979 1/2-Drive Drag Link Driver

Fig. 164. Blackhawk 49979 1/2-Drive Drag Link Driver, with Inset for Top View, 1945.

Fig. 164 at the left shows a 1/2-drive Blackhawk 49979 drag link driver, marked "Made in U.S.A." with a "-5" date code, and with a "U.S. Pat's. 1927844 RE.19,287" patent notice.

The overall length is 1.8 inches, and the finish is chrome plating.

The "-5" date code indicates production in 1945 or 1955, though the former date is probably more likely.

3/8-Drive Socket and Tools

Although Blackhawk had originally planned to offer a full range of features for its 3/8-drive Lock-On tools, the sockets in particular turned out to be too small for release buttons. Blackhawk responded by designing the intermediate 7/16-drive Lock-On tools, and provided 7/16-drive sockets covering almost the same range as the 3/8-drive and 1/2-drive sizes combined.

Blackhawk continued to produce the 3/8-drive Lock-On tools for a number of years, but without the convenience of the built-in release buttons. As these tools are relatively rare, it appears that only a small number of the 3/8-drive Lock-On tools were sold, probably because of the inconvenience of the manual release.

Eventually Blackhawk recognized that 3/8-drive didn't really need the Lock-On feature, and 3/8-drive tools went back to using detent balls. A few examples of these can be seen in a section on Later 3/8-Drive Tools.

7810S 3/8-Drive 12-Point Socket

Fig. 165. Blackhawk 3/8-Drive 7810S 5/16 Socket, with Inset for Drive End, ca. 1930-1933.

Fig. 165 shows another early example of a Lock-On socket, a Blackhawk 7810S 5/16 socket marked "U.S.A." and "Pat. Pend." but with no patent numbers.

As was the case for the previous figure, this socket has a hole for the locking pin, but was not fitted with a release button. The socket design includes a thin knurled band, mostly decorative in nature, and the finish is polished chrome.

The 78xx series sockets are not listed in a 1929 Blackhawk catalog, but are listed (without release buttons) in the MG330 catalog of early 1930. Together with the patent pending status, this leads to an estimated manufacturing date in the range 1930-1933.

The inset shows the scalloped indentations machined into the drive end, as discussed in the prior figure.

9210S 3/8-Drive Extension

Fig. 166. Blackhawk 9210S 3/8-Drive Lock-On Extension, ca. 1934-1937.

Fig. 166 shows a Blackhawk model 9210S 3/8-drive extension, marked "Made in U.S.A." with the "U.S. Pats. 1,927,844 RE19,287 1,982,008" patent notice.

The overall length is 10.0 inches.

The extension is equipped with a slanted locking pin, and the driven end has a cross-bar hole (with a detent ball) for use as a T-handle.

34981 3/8-Drive Ratchet

Fig. 167. Blackhawk 34981 3/8-Drive Gearless Ratchet, with Insets for Side View and Marking Detail, 1943.

Fig. 167 shows a rare 3/8-drive Blackhawk 34981 "Free Wheeling" gearless ratchet, marked "Made in U.S.A." with a "U.S. Pats. 2003155 RE19287 1927844" patent notice. The side view in the top inset includes the admonition "Keep Well Oiled" and a "-3" date code, interpreted below as indicating 1943.

The overall length is 7.0 inches, and the finish is cadmium plating.

The Gripline handle with a date code of "-3" indicates a manufacturing year of 1943, which is consistent with the cadmium plated finish.

34986 3/8-Drive Flex-Head Breaker Bar

Fig. 168. Blackhawk 34986 3/8-Drive Flex-Head Breaker Bar, 1944.

Fig. 168 shows a 3/8-drive Blackhawk 34986 flex-head breaker bar, marked "Made in U.S.A." with a "4" date code, and with a "U.S. Pats. RE19,287 1,927,844" patent notice.

The overall length is 8.1 inches, and the finish is cadmium plating.

As with the previous figure, this tool has a Gripline style handle with raised ribs along the axis. The handle style with the date code of "4" indicates a manufacturing year of 1944, which is consistent with the cadmium plated finish.

30220 3/8-Drive Universal Socket

Fig. 169. Blackhawk 30220 3/8-Drive 5/8 Universal Socket, with Insets for Broaching and Marking Detail, 1943.

Fig. 169 shows a 3/8-drive Blackhawk 30220 5/8 universal socket, marked "Made in U.S.A." with a "-3" date code, and with a "U.S. Pat's. 1927844 RE.19,287" patent notice.

The finish is cadmium plating.

The cadmium finish and "-3" date code indicate production in 1943.

3/4-Drive Sockets and Tools

Blackhawk had offered 3/4-drive tools during the mid 1920s as part of its Q.D. product line, and by 1930 Blackhawk was offering 3/4-drive tools in the Lock-On series as well.

The model numbers for the initial 3/4-drive Lock-On tools were derived by appending an "N" (perhaps for "New") to the older Q.D. numbers, at least where the tools were otherwise comparable. These numbers were a bit confusing though, and sometime in the mid 1930s Blackhawk revamped their model numbers, assigning a 6xxxx series to the 3/4 drive size.

Early D46XN 3/4-Drive Socket

Our first example for the 3/4-drive sockets is unusually significant, in that it shows an early patent-pending Lock-On socket with apparent hot-broached construction.

Fig. 170. Blackhawk 3/4-Drive D46XN 1-7/16 Socket, with Panels for Drive End and Broaching, ca. 1930-1933.

Fig. 170 shows a 3/4-drive 12-point Blackhawk model D46XN 1-7/16 socket, marked "U.S.A." and with a "Pat. Pend." notation. The photograph has been arranged as a triptych, with the full view in the center, flanked by the drive end on the left and the broached end on the right.

The 3/4-drive DxxXN socket series was the double-hex continuation of the xxXN models. The DxxXN sockets were not listed in the 330MG catalog of 1930, so these models were probably introduced sometime in late 1930 or 1931. Together with the patent pending status, this leads to an estimated manufacturing date in the range of late 1930 to 1933.

The drive end shown in the left panel has the scalloped indentations seen on other early Lock-On sockets, and the hole for the locking pin (with no release button) is visible at the front.

The most notable aspects of this socket concern the construction techniques, in particular the broaching and contour grinding. A careful examination of the broached area shows only smooth walls with no trace of chatter marks, indicating the use of a hot-broaching process. The residual material from the broaching has been carefully clipped against the walls, apparently by a second trimming or boring operation.

This is a significant finding, as it makes Blackhawk possibly the first tool company to use hot-broached (or hot-forged) construction for its sockets. (An advertising blurb in the 1941 catalog makes this claim, but provided no details.) Hot-broaching was an important development for socket technology, and this reinforces Blackhawk's status as an innovator. Other companies were not far behind though; Snap-On may have done some hot-broaching as early as 1934, and Duro Metal Products filed its important hot-broach patent #2,027,922 in 1935.

D60XN 3/4-Drive Socket with Patent Numbers

Fig. 171. Blackhawk 3/4-Drive D60XN 1-7/8 Socket, with Insets for Drive End and Broaching, ca. 1934-1935.

Fig. 171 shows a 3/4-drive Blackhawk D60XN 1-7/8 socket, marked "Made in U.S.A." with a "U.S. Pats. 1927844 RE.19287 1982008" patent notice.

T4XN 3/4-Drive Sliding-Tee Breaker Bar

The next several figures show examples of early 3/4-drive Lock-On tools, dating from around the same time as sockets in the previous two figures.

Fig. 172. Blackhawk T4XN 3/4-Drive Sliding-Tee Breaker Bar, with Inset for Marking Detail, ca. 1930-1932.

Fig. 172 shows an early 3/4-drive Blackhawk T4XN sliding-Tee breaker bar, marked "U.S.A." with a "Pat. Pend." patent notice.

The overall length is 18.0 inches, and the finish is chrome plating.

The drive stud is fitted with a non-slanted locking pin, making this example one of the first generation of Lock-On tools. The patent pending notation refers to the early Lock-On patent #1,896,645, filed in 1929 and issued in 1932.

The T4XN breaker bar was designed to work as a T-handle with other extensions, so the bar has a stop ball at only one end. The bar has a diameter of 13/16 inches, the same size as used by Snap-On tools.

T8XN 3/4-Drive 8 Inch Extension

Fig. 173. Blackhawk T8XN 3/4-Drive 8 Inch Extension, with Inset for Construction Detail, ca. 1932-1934.

Fig. 173 shows a 3/4-drive Blackhawk T8XN 8 inch Lock-On extension, marked "U.S.A." with a "Pat. Pend." patent notice.

The overall length is 8.5 inches, and the finish is chrome plating.

The drive stud is equipped with a slanted locking pin for easy insertion, but the drive end does not include a release button. The patent pending status refers to patent #1,927,844, issued in 1933 and describing the slanted locking pin seen here. as seen in the photograph here.

The drive head includes a cross-bar hole with a detent ball, allowing use as a T-handle as well. The standard cross-bar was the Blackhawk Model T4XN shown above, which had a diameter of 13/16 inches and a length of 18 inches. Note that this 13/16 diameter is the same as that used by Snap-On for their 3/4-drive tools, allowing the Blackhawk and Snap-On tools to be used interchangeably.

916N 3/4-Drive Ratchet with T113XN Drive Plug

Fig. 174. Blackhawk 916N 3/4-Drive Ratchet, with Inset for Side View, ca. 1932-1934.

Fig. 174 shows a 3/4-drive Blackhawk 916N ratchet with a forged flat handle, marked "Blackhawk Mfg. Co." and "Milwaukee Wis. Made in U.S.A." in forged raised letters. The face plate is stamped with the model number and a "Patents Pend." notice.

The overall length is 16.0 inches. and the finish is chrome plating with polished faces.

The ratchet mechanism uses a 16-tooth gear, the same as in the very similar Q.D. predecessor Blackhawk 916 Q.D. Ratchet. The main difference between the two models is the use of a drive opening with slots on two adjacent faces, to accept the locking pins of the T113XN drive plug.

The model 916N ratchet was offered as early as 1930, but this particular example is probably from 1932 or later, as the T113XN drive plug has slanted locking pins.

60000-Series 3/4-Drive Sockets and Tools

In the mid 1930s Blackhawk updated the 3/4-drive model numbers to the 60000 series, using 60xxx numbers for sockets and 69xxx numbers for drive tools. For the sockets, the change to the 60000 series was not merely cosmetic, as the socket design was changed from tapered walls to straight walls. The 3/4-drive product line had previously offered sockets only in the tapered design, unlike the 1/2-drive line, which had offered both straight (66xx) and tapered (84xx) sockets.

The change to the new numbering system appears to have taken place in 1937, as a price list dated in April of 1937 includes a cross-reference of old and new numbers, and states that both numbers can be used for ordering in 1937.

The next several figures will show examples of 60000-series sockets and tools.

60134 3/4-Drive 8-Point Socket

Fig. 175. Blackhawk 3/4-Drive 60134 1-1/16 8-Point Socket, with Insets for Broaching and Marking Detail, ca. 1937.

Fig. 175 shows a rare early 3/4-drive Blackhawk 60134 1-1/16 8-point socket, marked "U.S.A." with a "Pat. Pend." notice.

60042 3/4-Drive 12-Point Sockets

Fig. 176. Blackhawk 3/4-Drive 60042 1-5/16 Sockets, with Inset for Date Codes.

Fig. 176 shows a pair of 3/4-drive Blackhawk model 60042 1-5/16 Lock-On sockets, both marked "Made in U.S.A." and with the "U.S. Pats. RE19287 1,927,844" patent notice. The insets show the date codes for the sockets, "3" on the left and "-6" for the right.

The lefthand socket has a cadmium finish, which is consistent with a manufacturing date of 1943. The righthand socket is finished in polished chrome, which again is consistent with manufacture in 1946. These sockets contributed to the understanding of the date code system explained earlier, as the presence of a cadmium finish places the date of manufacture within the wartime years.

600xx 3/4-Drive 12-Point Sockets

Fig. 177. Blackhawk 3/4-Drive Lock-On Sockets, with Inset for Date Codes, from Left: 60042 (1-5/16), 60050 (1-9/16).

Fig. 177 shows another paired comparison of 3/4-drive Lock-On sockets, this time with a model 60042 1-5/16 socket on the left (the same as shown in the previous figure), and a model 60050 1-9/16 socket on the right. Both are marked "Made in U.S.A." and "U.S. Pats. RE19287 1,927,844", as expected for Lock-On sockets.

The somewhat odd-looking inset in the photograph shows the markings and date codes for the sockets.

The socket on the left has the standard polished chrome plating and a digit code of "-6", while the righthand socket has a thin cadmium plating and a digit code of "4". These sockets contributed to the understanding of the date code system explained earlier, and based on the codes were manufactured in 1946 and 1944 respectively.

69999 3/4-Drive Ratchets

The next two figures show examples of the model 69999 ratchet, the successor to the 916N ratchet.

Fig. 178. Blackhawk 69999 3/4-Drive Ratchet, with Insets for Side View and Marking Detail, 1939.

Fig. 178 shows a 3/4-drive Blackhawk 69999 ratchet with a forged flat handle, fitted with a model 69989 drive plug. The face plate is stamped with the model and "U.S. Pats. RE19287 1927844", followed by a "-9" date code and an "FR" notation, as shown in the middle inset. The handle has forged-in markings "Blackhawk Mfg. Co. Milwaukee Wis." and "Made in U.S.A." on both sides, plus a small "DIF" forge mark on one side (see lower inset).

The overall length is 15.9 inches, and the finish is chrome plating.

The "-9" date code indicates production in 1939, as this ratchet model had been discontinued by 1947 or earlier. This ratchet was acquired as part of a No. 14BD 3/4-drive socket set, and most of the other pieces in the set were also marked for 1939 production. The meaning of the "FR" code following the date digit is not yet known, but has been observed on a number of Blackhawk tools.

The lower inset shows a close-up of the "DIF" forging mark, a code used to indicate production by Interstate Drop Forge. Interstate was a merchant drop-forging company in Milwaukee, established in 1920 and serving industrial customers as well as tool companies. (Interstate Drop Forge also made some ratchet handles for Snap-On.)

Fig. 179. Blackhawk 69999 3/4-Drive Ratchet, with Inset for Detail, 1940.

Fig. 179 shows another example of the Blackhawk 69999 ratchet. The forged flat handle is marked "Blackhawk Mfg. Co. Milwaukee, Wis." and "Made in U.S.A." in raised letters, and the face plate is stamped "U.S. Pats. RE19287 1927844" followed by a "-0 FR" code.

The overall length is 15.9 inches. Most of the finish has been lost, but was originally chrome plating.

The inset shows the date code marking "-0", which for this tool indicates production in 1940. (This ratchet model had been discontinued by 1947 or earlier.) An additional code "FR" follows the date code digit, a notation that has been observed on other Blackhawk tools as well. This might stand for "Factory Reconditioned", but meaning is still uncertain.

69998 3/4-Drive Flex-Head Breaker Bar

Fig. 180. Blackhawk 69998 3/4-Drive Flex-Head Breaker Bar, with Insets for Construction and Marking Detail, 1943.

Fig. 180 shows a 3/4-drive Blackhawk 69998 flex-head breaker bar, marked "Made in U.S.A." with a "-3" date code, and with a "U.S. Pats. RE19287 1927844" patent notice.

The overall length is 19.8 inches, and the finish is cadmium plating.

The Gripline handle is provided with a cross-bar hole, and in addition has been drilled out for use with an extension bar. The upper right inset shows the details of this construction.

69994 3/4-Drive 17 Inch Extension

Fig. 181. Blackhawk 69994 3/4-Drive 17 Inch Extension, with Inset for Marking Detail, ca. 1935-1938.

Fig. 181 shows a 3/4-drive Blackhawk 69994 17 inch extension, marked "Made in U.S.A." with a "U.S. Pat's. 1,927,844 RE19,827 1,982,008" patent notice.

The overall length is 17.0 inches, and the finish is chrome plating.

The drive head includes a cross-bar hole for use with a 13/16 diameter cross-bar, as described for the Blackhawk T8XN Extension shown previously. The Model 69994 extension was the successor to the T17XN model produced earlier.

This extension isn't marked with a date code, suggesting that it may have been made before the advent of the date code system.

69966 3/4-Drive Double Socket

Fig. 182. Blackhawk 69994 3/4-Drive 15/16x1-3/16 Double Socket, with Inset for Broaching.

Fig. 182 shows an unusual 3/4-drive Blackhawk 69966 15/16x1-3/16 double socket, possibly intended for lug-nut applications. The socket is marked "Made in U.S.A." with a "9" date code and the standard "U.S. Pats. 1927844 RE.19827" patent notice.

The overall length is 3.3 inches, and the finish is cadmium plating.

The socket is fitted with a Lock-On release button in the center, allowing an extension to be inserted and locked from either side.

We haven't yet found a catalog reference for this tool, and it's possible that it might have been a special-order item. Without any other guidelines for the manufacturing date, the "9" date code could indicate production in either 1939 or 1949.

7/8-Drive and 1 Inch Drive Tools

During the 1920s Blackhawk's largest drive size was 7/8-drive, and production of this size continued into the mid 1930s. The 7/8-drive size was still listed in a 1935 catalog, but a price list from April of 1937 shows only the 1 inch drive size. The new 1 inch drive sockets and tools were given model numbers in an 80000 series, with 80xxx numbers for sockets and 89xxx number for drive tools.

The 1 inch drive tools used interchangeable handles to reduce the already considerable weight of these massive tools. The standard finish was cadmium plating.

D56XX 7/8-Drive Socket with Release Button

According to the 1934 Blackhawk catalog MG534, release buttons were available at that time, but only for the 7/8-drive sockets. This next figure shows an example.

Fig. 183. Blackhawk 7/8-Drive D56XX 1-3/4 Socket, with Insets for Broaching and Marking Detail, ca. 1934-1938.

Fig. 183 shows a 7/8-drive Blackhawk D56XX 1-3/4 socket with a release button, marked "Made in U.S.A." with a "U.S. Pats. 1927844 RE.19287 1982008" patent notice.

In this socket we see the long-awaited release button for the first time. The button consists of a plunger with an expanded ring, and is installed in a stepped hole. After the plunger was installed in the hole, the outer opening was crimped to capture the button, similar to the way friction balls were installed.

The patent notice is the same as that in the previous figure.

920 7/8-Drive Ratchet

Fig. 184. Blackhawk 920 7/8-Drive Ratchet, ca. 1930-1934.

Fig. 184 shows a Blackhawk 920 7/8-drive ratchet with a heavy forged flat handle. The handle is marked "Blackhawk Mfg. Co." with "Milwaukee, Wis." and "Made in U.S.A." in forged raised letters.

The overall length is 20.0 inches, and the finish is cadmium plating.

The ratchet mechanism uses a 16-tooth drive gear, and the drive opening has a slot for use with a model T13XX Lock-On drive plug.

T9XX 3/4-Drive To 7/8-Drive Adapter

Fig. 185. Blackhawk T9XX 3/4-Drive To 7/8-Drive Adapter, ca. 1932-1934.

Fig. 185 shows a rare Blackhawk T9XX 3/4-drive to 7/8-drive adapter, marked "U.S.A." with a "Pat. Pend." notation.

The overall length is 2.2 inches, and the finish is cadmium plating.

The pending status refers to patent #1,927,844, issued in 1933. The patent describes the use of a slanted locking pin, as seen in the photograph here.

80076 1 Inch Drive 2-3/8 6-Point Socket

Blackhawk also produced Lock-On sockets in 1-inch drive sizes, as the next figure shows.

Fig. 186. Blackhawk 1 Inch Drive 80076 2-3/8 6-Point Lock-On Socket, with Inset for Broaching, 1945.

Fig. 186 shows a Blackhawk 80076 2-3/8 socket, marked "Made in U.S.A." and "U.S. Pats. RE19287 1927844".

The finish on the socket is cadmium plating, which according to the catalogs was the standard finish for the 1-inch drive tools. The date code is "5", which could indicate production in 1945 or 1955, but as the socket was acquired with other tools dating to the mid 1940s, the likely manufacturing date is 1945.

The Blackhawk 1-inch drive sockets were available in 6-point (single hex) broachings, with sizes ranging from a 1-1/16 model 80034 to the 3-1/8 model 80100. Sockets with 4-point (single square) broachings were also available, but in only three sizes, 1-1/16 (model 81034), 1-1/4 (model 81040), and 1-7/16 (model 81046).

89987 1 Inch Drive Ratchet

Fig. 187. Blackhawk 89987 1 Inch Drive Ratchet, Top View, 1943.

Fig. 187 shows a Blackhawk 89987 1 inch drive ratchet, marked "Made in U.S.A." and "U.S. Pats. 1927844 RE.19287 1995009", plus an additional "Other Pat. Pend." notice.

The overall length is 9.0 inches, and the finish is cadmium plating.

The ratchet mechanism uses a 28-tooth gear and is covered by the same patent #1,995,009 used by the ratchet adapters described above. The pending status is for patent #2,286,917 which was issued to S. Mandl in 1942.

Fig. 188. Blackhawk 89987 1 Inch Drive Ratchet, Side View, 1943.

Fig. 188 at the left shows the 89987 ratchet from the side.

The ratchet has a stub handle designed to accept two types of handle extensions, a model 89997 bar that fits into the inner bore, or a model 89989 tubular handle that slids over the outside. In the former case, the lock button on the 89997 bar fits into the hole in the ratchet handle, and in the latter case, the lock button on the ratchet slips into a hole in the tubular handle.

In either configuration, the 89989 tubular extension and 89997 bar can be coupled together to provide even greater leverage.

89998 1 Inch Drive Sliding Tee Head

Fig. 189. Blackhawk 89998 1 Inch Drive T-Slider, with Insets for End View and Markings, 1943.

Fig. 189 shows a Blackhawk 89998 1 inch drive sliding Tee head, marked "Made in U.S.A." and "U.S. Pats. 1927844 RE.19287".

The overall length is 3.5 inches, and the finish is cadmium plating.

The sliding head was intended for use with the model 89997 bar, a hefty tool with a 23 inch length and 1-1/8 inch diameter. The 89997 bar also served as the handle for the 89987 ratchet head.

The lower left inset shows the "-3" date code marking, which in this case could indicate production in either 1943 or 1953, as cadmium finishes were standard for the 1 inch drive tools and sockets. However, the 89987 ratchet acquired in the same lot had a patent pending notice that makes 1943 the likely production year.

The righthand inset shows an end view of the tool, with the end broached for additional use as a short extension. The cross-bar hole is equipped with a detent ball to help hold the position on the bar.