Alloy Artifacts

Identification Marks on Tools (Excluding Sockets)

After reviewing the registered trademarks in the previous section, let's look now at the various informal marks and brands used by Duro and Indestro. Where possible, the figures will show combinations of an informal mark with a registered trademark, in order to establish a firm connection with the companies' products.

Chromium-Vanadium

As chrome alloy tools became more in demand, Duro and Indestro started using the mark "Chromium-Vanadium" to indicate these high-end (and more expensive) tools. Although many other manufacturers also made chrome alloy tools, these were usually marked using the abbreviated "Chrome Vanadium" phrase, so the use of the full element names can help identify particular Duro and Indestro pieces.

The date for the first use of the Chromium-Vanadium mark is not known, but we do have direct evidence that it was in use by 1931. By fortunate circumstance, we were able to acquire a rare early Indestro Chromium-Vanadium socket set, with a dated sales receipt from 1931. The set consists of ten 12-point sockets, a speeder, T-slider, ratchet adapter, extensions, and a universal, with most of the pieces being marked "Chromium-Vanadium". The speeder is also marked "Indestro Chicago", and the metal box has an Indestro decal on the top.

The set was purchased from a Western Auto store, and a check of their 1932 catalog shows that a "Chromium Vanadium" socket set was available, with a description exactly matching the set shown below.

Indestro 1/2-Drive Chromium-Vanadium Socket Set

Fig. 3 shows the Indestro 1/2-drive Chromium-Vanadium socket set from 1931. The ten sockets are marked "Chromium-Vanadium" except for one, and all of the drive tools are similarly marked, except for the unmarked universal and double-male extension.

Fig. 3. Indestro 1/2-Drive Chromium-Vanadium Socket Set, 1931.

The sockets in the set will be examined in greater detail in a later section, when we look at 12-Point Sockets.

Indestro 1/2-Drive Chromium-Vanadium Ratchet Adapter

Fig. 7. Indestro 1/2-Drive Chromium-Vanadium Ratchet Adapter, 1931.

Fig. 7 shows the ratchet adapter from the set, marked "Chromium-Vanadium" and "1-2" with stars on either side. The overall length (extended) is 3.2 inches.

The 1932 Western Auto catalog called this tool simply a ratchet rather than a ratchet adapter. By 1933 the Western Auto socket sets included a true ratchet instead of the adapter, a model based on Duro's patent #1,902,878.

Indestro 1/4-Drive Chromium-Vanadium Socket Set

Fig. 8. Indestro 1/4-Drive Chromium-Vanadium Socket Set, ca. 1935-1936.

Fig. 8 shows another Indestro socket set, this time a 1/4-drive set with "Chromium-Vanadium" prominently featured in the logo decal. In this set the individual tools are not marked except for sizes on the sockets. (This set will be mentioned again in the section concerning socket identification.)

Indestro Polygon

Indestro made use of an "Indestro Polygon" brand around the same time that the "Chromium Vanadium" mark was in use. Currently the known examples are all offset box-end wrenches with 12-point openings, but it may have been used for other tools as well.

Although the dates are uncertain, the Indestro Polygon wrenches are believed to have been made in the late 1920s or early 1930s.

Indestro Polygon Offset Box-End Wrench

Fig. 9. Indestro Polygon 5/8x11/16 Offset Box-End Wrench, with Insets for Side View and Reverse Detail.

An example of the Polygon brand is shown in Fig. 9, an Indestro Polygon 5/8x11/16 offset box wrench marked "Chromium-Vanadium" on the reverse. The overall length is 9.8 inches, and the finish is plain steel.

The upper inset shows a side view of the wrench to illustrate the construction details. The shank is roughly oval in cross-section, with a smoothly rounded top and bottom and clipped sides. A particular detail to note is that the offset shank joins the box end over the full width of the box, without a lip above and below the join.

Later construction for Duro and Indestro offset box wrenches generally had the shank joining near the middle of the box end, with a distinct lip above and below. See for example the Indestro Super 731A Wrench shown later in this page.

Indestro Polygon Chromium-Vanadium Wrenches

Fig. 10. Indestro Polygon Wrenches with "Chromium-Vanadium" Mark.

Fig. 10 illustrates the connection between the Polygon and "Chromium-Vanadium" marks, showing the reverse side of three Indestro Polygon wrenches.

Super-Quality

Somewhat after the use of the "Chromium-Vanadium" mark, Indestro started using the phrase "Super-Quality" as a brand for its Chrome alloy tools. This use of "Super-Quality" is the obvious forerunner for the eventual Indestro "Super" line of chrome-alloy tools.

Fig. 11. Indestro Socket Set of Chrome Vanadium Steel with "Super-Quality" Logo.

Fig. 11 at the left shows one example of this, a 1/4-drive socket set with an Indestro logo showing "Super-Quality" and "Chrome Vanadium Steel". The tools in this set are marked "Chromium-Vanadium", and some have part numbers that in later catalogs would be identified as part of the Indestro "Super" line.

Although the time of the first use of "Super-Quality" is unknown, the mark was definitely in use by 1938, as the Indestro catalog for that years shows a number of examples. In this early usage the "Super-Quality" mark apparently referred not only to the alloy steel, but to a premium chrome-plated finish as well.

A 1941 Indestro catalog shows extensive use of the "Super-Quality" mark for the chrome alloy tools, both on the tool illustrations and on advertising displays. Interestingly, the sockets shown are referred to as "Super-Quality" in the text but are marked "Chromium-Vanadium" in the illustrations, suggesting that the change may have been phased in over a period of time.

In Fig. 12 we see several more examples of the use of the "Super-Quality" mark, this time on the tools themselves, along with other identifying marks.

Fig. 12. Duro-Chrome and Indestro Wrenches with Super-Quality and X-Circle Marks.

The wrench at the top is marked Indestro and has the part number 714, which later catalogs show as part of the Indestro Super line. The two middle wrenches are marked with "Super-Quality" and the X-Circle mark, and in addition show the streamlined design in the polished raised panel area.

The bottom wrench is marked Duro-Chrome 2013 and shows the X-Circle mark as well. The raised panel streamlined design is comparable to that in the middle two wrenches, showing the commonality of design among all four tools.

Indestro 763 9/16x5/8 S-Shaped Box-End Wrench

Fig. 13. Indestro 763 9/16x5/8 S-Shaped Box-End Wrenches, with Inset for Reverse Detail.

Fig. 13 shows another example of the "Super-Quality" mark, a rare Indestro 763 9/16x5/8 S-shaped box-end wrench marked "U.S.A." and "Super-Quality". The inset shows the reverse with "Chrome Vanadium Steel" in a particular slanted font, which will be discussed in a later section.

The overall length is 8.0 inches, and the finish is plated chrome with polished box ends.

Indestro Super

We've mentioned the Indestro Super brand several times as the successor to the Super-Quality mark, so it's time to show some examples. The transition date from Super-Quality to Indestro Super is a bit uncertain, as we currently don't have sufficient catalog coverage or other information. However, the first example below at least suggests a likely time frame.

Indestro Super 2 Tappet Wrench

Fig. 14. Indestro Super Model 2 1/2x9/16 Tappet Wrenches, with Inset for Reverse Detail, ca. 1944-1945.

Fig. 14 shows an Indestro model 2 1/2x9/16 tappet wrench, stamped "Indestro Super" on the face with "Forged in U.S.A." on the reverse. The overall length is 8.0 inches.

The finish is plain steel with traces of the original cadmium plating, and this provides a helpful clue to the manufacturing date.

Indestro and Duro-Chrome wrenches were generally given chrome plated finishes after the early 1930s, except for the period of wartime shortages in 1944-1945. Tools made at that time generally substituted cadmium (or plain) finishes for chrome, so it's likely that this wrench was made in 1944-1945.

This tool is probably our earliest example of the Indestro Super marking, and indicates that the transition likely occurred around that time.

Indestro Super 731A Offset Box-End Wrench

Fig. 15. Indestro Super 731A 9/16x5/8 Offset Box-End Wrench, with Insets for Side View and Reverse Detail.

Our next example is shown in Fig. 15, an Indestro Super 731A 1/2x9/16 offset box-end wrench. The hexagonal shank has raised panels in the streamlined design, with "Indestro Super" on the front and "Forged in U.S.A." on the reverse. The overall length is 9.4 inches.

The finish is chrome plating with polished ends.

Handy-Hex

The next figure shows a recently acquired tool that proved to be the "missing link" to a brand name used by Duro in the late 1920s or early 1930s. The front side of the wrench is clearly marked as Duro-Chrome model number 268, which is listed as a Chrome Vanadium brake wrench (Ford-specific) in catalog 38M and others. But on the back side (see inset), it's also marked as "Handy-Hex".

The "Handy-Hex" mark had been the source of a long-standing mystery for me, as I had acquired a number of wrenches of this brand, but had been unable to trace the maker.

Duro-Chrome 268 "Handy-Hex" 7/16x1/2 8-Point Brake Wrench

Fig. 16 shows a Duro-Chrome 268 7/16x1/2 8-point brake wrench, marked "Chrome Vanadium Steel" with "Ford Brakes" and "Handy-Hex" on the reverse. The overall length is 11.0 inches.

Fig. 16. Duro-Chrome 268 7/16x1/2 8-Point Brake Wrench, with Inset Showing "Handy-Hex" Brand.

When this wrench turned up, I reexamined the markings on some older Handy-Hex pieces. Both examples were deep-offset wrenches marked "Chrome Vanadium Steel", and had model numbers 02055 (13/16 x 7/8) and 02056 (15/16 x 1). (One of these Handy-Hex wrenches is shown in the next figure below.)

When I checked Duro-Chrome catalog 38M for this style of deep offset wrench, it listed model number 2055 with sizes 13/16x7/8, model 2056 with sizes 15/16x1, and an overlooked caption jumped out: "Handy-Twin-Hex"!

Putting together all of these clues, we can reconstruct the history of the Handy-Hex mark to go something like this. Sometime in the late 1920s, Duro produced a line of 6-point box-end wrenches and sold them under the Handy-Hex brand. When 12-point wrenches became popular (probably in the early 1930s), Duro offered 12-point Handy-Hex wrenches as well, adding an initial "0" to the old model numbers to distinguish the new models. Catalog 38M shows an example of this: a four-arm lug wrench is model 2099 for 6-point openings and model 02099 for 12-point. (One of the Handy-Hex wrenches even has the leading "0" hand-stamped.)

Later on in the 1930s, Duro reworked its offset wrench models again, offering only 12-point wrenches, branding them as Duro-Chrome instead of Handy-Hex, and reverting to the earlier 4-digit model numbers. But as a reminder for existing customers, the caption "Handy-Twin-Hex" pointed to the heritage.

Handy-Hex 02055 13/16x7/8 Offset Box-End Wrench

Fig. 17. Handy-Hex 02055 13/16x7/8 Wrench, with Inset for Reverse Detail.

Fig. 17 shows a Handy-Hex 02055 13/16x7/8 offset box wrench, marked "Made in U.S.A." with "Chrome Vanadium Steel" on the reverse.

The overall length is 12.6 inches, and the finish is a thin plating with a yellowish tint.

Select Steel

Duro and Indestro began using the phrase "Select Steel" in several variations as an informal trademark fairly early on, probably as soon as they needed to make a distinction between the more expensive Chrome Alloy steel and the less expensive "Select" alloy. Many of their tools are marked with the phrases "Forged Select Steel" or "Drop Forged Select Steel" (or other variations), and the catalogs have a section for "Select Steel" economy tools as well as the high-end "Chrome Alloy" tools. (As previously noted in the section on trademarks, Indestro did later register "Select Steel Tools" as a formal trademark.)

Fig. 18. Indestro Chicago Open-End Wrenches Showing "Drop Forged Select Steel".

Fig. 18 at the left shows the use of "Drop Forged Select Steel" on the reverse side of the Indestro Chicago wrenches, previously shown in the discussion of the Streamlined Design Trademark.

With the history of consistent use of "Select Steel" as a brand, this should serve as a clear identification for Indestro tools, especially when present with other distinctive marks.

X-Circle

We saw several examples of the X-Circle mark in Fig. 12 above, and Fig. 19 shows a Duro-Chrome 2015A 13/16x7/8 box-end wrench with a somewhat larger than normal X-Circle.

Fig. 19. Duro-Chrome 2015A 13/16x7/8 Box-End Wrench, with Insets for Reverse Side and X-Circle Logo.

Although the true origin of this mark is not known, a close examination of the logo in Fig. 19 at least suggests its likely meaning. Note that the sides of the "X" are actually curved, so that the mark resembles the letters "DC" butted together, with the circle overstriking the "D". Thus the mark is likely a stylized "DC" representing Duro-Chrome, much like the NB-Circle logo used by New Britain with its "None Better" trademark.

As far as is known, the X-Circle mark was used only on the chrome alloy tools.

Duro-Chrome 2081 Half-Moon Wrench

Fig. 20. Duro-Chrome 2081 9/16x5/8 Half-Moon Box Wrench, with Inset for Reverse.

Fig. 20 shows another example of the X-Circle mark, this time on a Duro-Chrome 2081 9/16x5/8 half-moon wrench, marked "Forged in U.S.A." with "Manifold & Starter" and an X-Circle on the reverse. The overall length is 7.2 inches.

This style of wrench is referred to as an "elbow wrench" in the Duro catalogs. The nearly identical (except for markings) Indestro 769 model is shown in Fig. 21 below.

Other Marks and Characteristics

In addition to the various marks described above, there are some lesser indications that may help to identify Duro/Indestro tools, at least if present in conjunction with other distinctive marks. One of these is the use of the phrase "Chrome Vanadium Steel" (or "Chromium Vanadium Steel") in a distinctive slanted font.

Indestro 769 9/16x5/8 Half-Moon Wrench

Fig. 21. Indestro 769 9/16x5/8 Half-Moon Wrench, with Inset Showing Slanted Font.

Fig. 21 shows an Indestro 769 half-moon wrench, marked "U.S.A." with "Super-Quality" on the front side. The inset shows the reverse side with an example of "Chrome Vanadium Steel" in the slanted font.

Although this slanted font could have been used by other manufacturers, currently the only examples known are on tools marked as or of apparent Duro/Indestro production.

Another example of the slanted font appears above on the Indestro 763 S-Shaped Wrench.

Curved Arc "Forged in U.S.A." Mark

Another marking style noted only on Duro-Chrome and Indestro tools is the use of the phrase "Forged in U.S.A." curved along a circular arc, typically stamped on a wrench head. Examples of this marking have been found on tools marked "Duro-Chrome" or "Super-Quality", or otherwise marked to indicate an alloy steel tool, but not on economy-grade Select Steel tools.

Fig. 22. Circular Arc "Forged in U.S.A." Mark on Several Duro-Chrome Wrenches.

Fig. 22 shows several examples of this marking.

Patent Numbers and Dates

Duro Metal Products was fairly prolific in its patent activities, as we saw in the Patent Table shown in the previous section. The tools produced under these patents were often marked with the patent number or date, and such patent markings may then serve as an important identification mark.

The figures below will show some examples of Duro and Indestro tools with patent markings.

Duro 672 Ratchet Handles, Patent #1,798,481

In some cases the patent number may be the only identifying mark on a tool, perhaps to allow the tool to sell with various private brandings, or with no other identification at all. An example of this is shown in Fig. 23, where we see three examples of the Duro model 672, an early ratchet handle. The ratchet at the top is marked "Duro Metal Products Co. 672" and "Patent Pending", and the one in the middle is similarly marked, except that it shows the actual patent #1,798,481.

Fig. 23. Duro 672 Ratchet Handles Showing Patent Status.

The ratchet on the bottom is identical to the other two and shows the same patent number, but is not marked with a maker or model number, showing only "Chicago, U.S.A.". The explanation is simple: this ratchet came from an Indestro-branded socket set, and in order to maintain the separation of the brand names, Indestro simply omitted the Duro branding and model number.

The patent information on these ratchet handles provides a rare opportunity to estimate the production date of a tool. The first ratchet handle, being marked "Patent Pending", would have been made during the interval between the filing of the patent application and the subsequent issue. The other ratchets are marked with the actual patent number, so by examining the document for patent #1,798,481, we can determine that the first ratchet was likely made between 1928 and 1931.

Indestro Socket Set, Patent #1,788,535

Fig. 24. An Indestro No. 1351 Socket Set, with Inset Showing Patent 1,788,535.

Fig. 24 below shows an example of a socket set identified only by a patent number, in this case the Duro Metal patent #1,788,535. After reviewing an Indestro catalog, the socket set matches the description and appearance of model No. 1351, but none of the tools are marked with a company name or part number. However, the bottom of the case is stamped with the patent number, as shown in the inset to Fig 11B. (The vintage price sticker is interesting as well.)

Duro Convertible L-T Handle, Patent #1,744,413

Fig. 25. Duro 1/2-Hex Drive L-T Convertible Breaker Bar.

Fig. 25 shows a convertible L-T handle frequently included in Duro and Indestro economy-line socket sets. The handle is marked only with "Made in U.S.A" and "Pat. No. 1,744,413"; the omission of the company name indicates that the tool was probably intended for contract production.

The particular tool is furnished with a 1/2-hex drive L-handle, but was also made with 1/2 square drive handle. The handle was part of a socket set in a box with a sliding lid. The finish is a heavy cadmium plating.

The patent #1,744,413 was issued in 1930 to E.H. Peterson, one of Duro's most active inventors. In operation, the tool converts to a T-handle by sliding the breaker bar out of the sheath, then inserting the short arm of the ell into the side of the sheath. The arm locks in place against an indentation in the wall of the sheath.

This tool is similar in operation to the Hinsdale T-L Handle; however, the Hinsdale tool is permanently assembled.

Duro-Chrome 678D 1/2-Drive Ratchet, Patent #1,902,878

One of the more notable Duro inventions described a novel way for constructing ratchets, and was issued as patent #1,902,878 in 1933. Instead of the conventional ratchet assembly held together with screws or rivets, the Duro design secured the parts with a pressed flange integral to the forging. This allowed Duro to produce a high-quality forged ratchet at a reasonably low cost, and the resulting products were sold widely into high-volume markets.

Probably the first market for these ratchets, and perhaps the impetus for their development, was as part of the Chrome-Vanadium Socket Wrench Set offered by Western Auto in their 1933 catalog. This set sold for a mere $5.68 and included the ratchet, a speeder, a T-slider, two extensions, a universal, and ten 12-point sockets, truly a stunning value for a set of alloy steel tools. (This set was very similar to the Indestro Chromium-Vanadium Set shown earlier, with the ratchet adapter replaced by the pressed-flange ratchet.)

Fig. 26. Duro-Chrome 678D 1/2-Drive Ratchet, with Inset for Reverse, ca. 1932-1936.

Fig. 26 shows our first example of the pressed-flange design, a 1/2-drive Duro-Chrome model 678D reversible ratchet, marked with a bold "Duro-Chrome" on a raised panel in the center of the forged handle. The reverse shows a similar panel with "Made in U.S.A." and "Pat. No. 1902878". The overall length is 10.4 inches.

The finish is plain steel with a dark oxide coating.

This ratchet has a fairly coarse 18-tooth gear, but later versions of this model had a 36-tooth mechanism for a much finer action. The combination of the coarse action and plain finish suggests that this may be a very early model, possibly dating to the early 1930s.

One interesting feature is the provision of both male and female drive, as can be seen in the photograph. Male drive ratchets were becoming more popular in the 1930s and were gradually replacing the older female models. By providing both drive genders, Duro allowed the ratchet to work with older sets having double-male extensions and drive plugs.

The 1938 Duro-Chrome catalog also offered a similar model 677D non-reversible ratchet, fitted with a female-only drive gear. The pressed-flange ratchet design remained in production at least until the early 1960s, with catalog 37-M offering a model 676 female drive ratchet with a 36-tooth action.

Duro-Chrome 4487 1/4-Drive Ratchet, Patent #1,902,878

Fig. 27. Duro-Chrome 4487 1/4-Drive Ratchet, with Inset for Reverse.

The pressed-flange construction was also used for other drive sizes, as can be seen in Fig. 27, a 1/4-drive Duro-Chrome model 4487 ratchet. The handle has a forged "Duro-Chrome" on a raised panel, and a similar panel is marked "Made in U.S.A." and "Pat. No. 1902878" on the reverse. The overall length is 6.0 inches, and the finish is cadmium plating.

The ratchet mechanism has a 20-tooth gear and is fitted with a reversing lever, as with the previous example. This ratchet also offers both male and female drive.

Duro-Chrome 2114 Battery Pliers, Patent #D119,441

The next figure shows a pair of battery pliers with unusual box-end wrench handles, marked with a design patent.

Fig. 28. Duro-Chrome 2114 Battery Pliers.

In Fig. 28 we see the Duro-Chrome 2114 battery pliers, marked "Forged in U.S.A." with "Des. 119,441" for the design patent.

The design patent #D119,441 was issued on Mar. 12, 1940 to W.A. Sandy and assigned to Duro Metal Products.

That completes the section on the informal brands and marks useful for tool identification. In the next section, we'll take a look at Duro and Indestro sockets.