Diamond Calk Horseshoe Company
Table of Contents
- Introduction
- Adjustable Wrenches
- Pliers and Other Tools
- Contract Production
- References and Resources
- What's New (Last Updated Oct. 30, 2009)
Introduction
Company History
The Diamond Calk Horseshoe Company was founded in 1908 by Otto Swanstrom, a blacksmith operating in Duluth, Minnesota. As the name suggests, the company was formed to make calks and horseshoes, and their initial product was a patented insertable calk for horseshoes. (A calk is a gripping bit on a horseshoe, added for better traction on ice or slippery surfaces.)
Diamond was very successful in their calk and horseshoe business, but as the tractor and automobile reduced the need for horses and horseshoes, the company turned its forging skills to the production of adjustable wrenches.
An example of an early Diamond adjustable wrench can be seen in the illustration at the left, part of an advertisement placed in a 1922 issue of The Horseshoer's Magazine.
In the mid 1920s Diamond was selected as the supplier of adjustable wrenches for the Motor Tool Specialty Company, the distributor organization for the Snap-On Wrench Company. This must have been both a high honor and a tremendous boost for their sales efforts, as Diamond brand wrenches were shown together with the Snap-On sockets and drive tools. Snap-On continued to offer Diamond brand wrenches in its catalogs until the late 1930s, and when its own Blue Point brand adjustable wrenches were introduced, Diamond appears to have continued as the contract manufacturer.
Some time after the success of its adjustable wrenches, Diamond expanded its product line to include various styles of pliers, cutters, tin snips, auto (monkey) wrenches, and other tools.
In 1952 Diamond began offering tongue-and-groove pliers under the "Groove-Joint" brand name. These pliers were made with the ribs forged directly into the handles, rather than being cut by machine tools, and are believed to have been based on a patent licensed from Utica Tools. An example of the new tongue-and-groove pliers can be seen in the October 1959 issue of Popular Mechanics, in an advertisement for 12 Inch Groove Joint Pliers on page 307.
In 1958 the company changed its name to Diamond Tool and Horseshoe, dropping the reference to calks, and tools produced after this were marked with the new company name. The date of the change is based on the earliest public reference found, but in any event the advertisement cited in the previous paragraph confirms that the new name was being used by 1959.
Diamond Tool remained a family-owned business until 1981, when it was sold to the Triangle Corporation, the parent company of the combined Utica, Herbrand, and Bonney tool companies. Triangle itself was later acquired by Cooper Industries, the corporate parent to numerous other tool companies. Cooper Tools had also acquired the Crescent Niagara Corporation, the parent of Crescent Tools, and over time the production of Diamond adjustable wrenches was merged with the Crescent production.
Patents
| Patent No. | Inventor | Filed | Issued | Description | Examples |
|---|---|---|---|---|---|
| 1,320,828 | G.E. Lindberg | 02/19/1915 | 11/04/1919 | Horseshoe with Removable Calks | |
| 1,688,601 | A.R. Swanstrom | 12/20/1923 | 10/23/1928 | Horseshoe | |
| 1,850,816 | A.R. Swanstrom | 02/26/1931 | 03/22/1932 | Pitching Horseshoe | |
| 1,862,499 | A.R. Swanstrom | 11/19/1930 | 06/07/1932 | Horseshoe Calk | |
| 2,818,758 | J.E. Swanstrom et al | 03/27/1956 | 01/07/1958 | Spring-Loaded Pliers | |
| 2,849,908 | J.E. Swanstrom et al | 08/06/1957 | 09/02/1958 | Adjustable Wrench with Locking Mechanism | |
| 3,304,817 | J.E. Swanstrom et al | 02/26/1965 | 02/21/1967 | Chain Pipe Wrench | |
| 3,404,457 | J.E. Swanstrom, Sr. | 07/26/1966 | 10/08/1968 | Alloy Rivet for Pliers ("Copaloy") | |
| 3,739,664 | J.E. Swanstrom et al | 10/14/1971 | 06/19/1973 | Forging Method | H18P Pliers, H112P Pliers |
Trademarks
Diamond registered several trademarks, initially for their distinctive Diamond-Horseshoe logo, filed in 1921 with the first use listed as 1908. A later registration added the logo showing "DIAMOND" in a diamond shape, filed in 1925 with the first use listed as 1919. Their well-known "Diamalloy" trademark for alloy steel tools listed a first use in 1931.
In 1952 Diamond began using the "Groove-Joint" trademark for a line of tongue-and-groove pliers, and the trademark registration was filed in 1963. (By this time the company name had changed to "Diamond Tool and Horseshoe".)
| Text Mark | First Use | Date Filed | Date Issued | Registration | Notes |
|---|---|---|---|---|---|
| [Diamond Horseshoe Logo] | August, 1908 | 03/11/1921 | 05/29/1923 | 168,676 | Horseshoe and diamond with calk in the center. Renewed in 1943. |
| Diamond [Diamond Logo] | 1919 | 10/24/1925 | 02/16/1926 | 209,074 | Renewed in 1946 |
| Diamalloy [Diamond Logo] | Late 1931 | 12/14/1942 | 05/18/1943 | 401,456 | |
| Diamalloy [Diamond Logo] | Late 1931 | 09/08/1952 | 02/16/1954 | 585,695 | Coverage extended to tinner's snips and heavy-duty nippers |
| Groove-Joint | 06/04/1952 | 02/04/1963 | 07/07/1964 | 772,762 | Tongue-and-Groove Pliers |
Manufacturing Dates
Diamond tools are not known to be marked with a date code, so the estimation of manufacturing dates must be made based on other factors. The following list of observations may be helpful in estimating the manufacturing date for some tools.
- Plain (Non-Reinforced) Hanging Hole. Diamond's early adjustable wrenches were made with a plain hanging hole without a ridge around it. Based on a review of Snap-on catalogs, the plain hole continued in production until at least 1939.
- Diamalloy Trademark. The Diamalloy trademark was first used in late 1931.
- Reinforced Hanging Hole. Later adjustable wrenches (in sizes 12 inches and under) were made with a reinforcing ridge around the hanging hole. The exact date of the change is not known, but it probably went into effect in the early 1940s. (Note: wrenches larger than 12 inches had tapered handles and continued to use a plain hanging hole.)
- Broached Hanging Hole. At some point Diamond began offering adjustable wrenches with a broached (double-hex) hanging hole, similar to the models made by the J.P. Danielson company. These appear to have been available only for a relatively brief span, probably in the early to mid 1940s. (A Diamond catalog from 1948 does not show broached holes.)
- Diamond Tool and Horseshoe Name. By 1959 the company name had been changed from "Diamond Calk Horseshoe" to "Diamond Tool and Horseshoe".
- Extended Panel for Adjustable Wrenches. By 1983 adjustable wrenches were being made with the depressed panel extending all the way to the adjusting knurl, to provide easier access.
- "No Hammering" Marking. By 1983 adjustable wrenches included a "No Hammering" warning forged into the shank.
Adjustable Wrenches
Diamond's original adjustable wrenches from the 1920s were marked "Tool-Steel Drop-Forged" (or equivalent), which was likely a high-carbon steel. After the introduction of "Diamalloy" brand alloy steel tools in 1931, Diamond continued to offer its tool steel models as a lower cost alternative, and these remained available until at least the 1960s.
Early "Tool Steel" 4 Inch Adjustable Wrench
![[Diamond Tool Steel 4 Inch Adjustable Wrench]](Photos/tools/diamond_4in_adj_b_cropped_inset.jpg)
Fig. 1 shows an early Diamond adjustable wrench in the ever-popular 4 inch size, marked "Diamond Calk Horseshoe Co." and "Duluth, Minn." with the Diamond-Horseshoe logo, a registered trademark of the company. The reverse markings show "Diamond" in a diamond-shaped logo, with "Tool-Steel", "Drop-Forged", and "Made in U.S.A." at the end.
The overall length is 4.4 inches, and the maximum opening is 0.5 inches.
The finish is worn to reveal a copper plating underneath, and may be either nickel or chrome on top.
This example has the early version of the Diamond-Horseshoe logo, and if you look carefully at the logo, you can see that the diamond has a calk in the center.
Another detail to note is that the hanging hole does not have a reinforcing ring around it. The illustrations in the Snap-On catalogs from 1927 through 1939 for Diamond (and later Diamalloy) wrenches show this type of plain hole. By 1948 the Blue-Point wrenches, still made by Diamond, are illustrated with a ring around the hole.
Early "Tool Steel" 6 Inch Adjustable Wrench
![[Diamond Tool Steel 6 Inch Adjustable Wrench]](Photos/tools/diamond_adj_6in_wrench_toolsteel_a215_plainhole_f_cropped_inset2.jpg)
Fig. 2 shows an early Diamond 6 inch adjustable wrench, marked "Diamond" and "Tool-Steel Drop-Forged" with the Diamond-Horseshoe logo forged into the shank, with "Diamond Calk Horse Shoe Co." and "Duluth, Minn. U.S.A." forged into the reverse. The wrench is also marked with a forged-in code "A215" near the adjusting knurl.
The overall length is 6.2 inches, and the maximum opening is 0.7 inches. The head thickness was measured at 0.47 inches.
The finish is plain steel.
"Tool Steel" 12 Inch Adjustable Wrenches
The next two figures show examples of Diamond "Tool Steel" 12 inch adjustable wrenches.
![[Diamond 12 Inch Adjustable Wrench]](Photos/tools/diamond_adj_12in_wrench_toolsteel_ringed_f_cropped_inset2.jpg)
Fig. 3 shows a Diamond 12 inch adjustable wrench, marked with the Diamond logo plus "Tool-Steel Drop-Forged" and "Made in U.S.A." forged into the front, with "Diamond Calk Horseshoe Co." and "Duluth, Minn." plus the Diamond-Horseshoe logo forged into the reverse.
The overall length is 12.2 inches, and the maximum opening is 1.3 inches. The head thickness was measured at 0.79 inches.
The finish is plain steel.
![[Diamond 12 Inch Adjustable Wrench]](Photos/tools/diamond_adj_12in_wrench_dth_f_cropped_inset2.jpg)
Fig. 4 shows a later Diamond 12 inch adjustable wrench, marked with the Diamond logo forged into the shank, followed by "Tool-Steel Drop-Forged" and "Made in U.S.A." in forged raised letters. The reverse is marked "Diamond Tool and Horseshoe Co." and "Duluth, Minn." in raised letters with the Diamond-Horseshoe logo.
The overall length is 12.2 inches, and the maximum opening is 1.3 inches. The head thickness was measured at 0.73 inches.
The finish is nickel plating.
The Diamalloy Era
In 1931 Diamond began using the "Diamalloy" trademark for their line of alloy-steel tools. The trademark was registered in 1942.
Early Diamalloy 10 Inch Adjustable Wrench
![[Diamond Diamalloy 10 Inch Adjustable Wrench]](Photos/tools/diamond_adj_10in_wrench_diamalloy_plainhole_f_cropped_inset2.jpg)
Fig. 5 shows an early Diamond Diamalloy 10 inch adjustable wrench, marked with "Forged Diamalloy Steel" and "Made in U.S.A." forged into the front, The reverse is marked with "Diamond Calk Horseshoe Co." and "Duluth, Minn." plus the Diamond-Horseshoe logo forged into the reverse. Both sides are also marked with the "10 In." nominal size.
The overall length is 10.1 inches, and the maximum opening is 1.1 inches. The head thickness was measured at 0.56 inches.
The finish is chrome plating with polished faces.
Diamalloy 4 Inch Adjustable Wrench
![[Diamond Diamalloy 4 Inch Adjustable Wrench]](Photos/tools/diamond_adj_4in_wrench_diamalloy_calk_f_cropped_inset.jpg)
Fig. 6 shows a Diamond Diamalloy 4 inch adjustable wrench, marked with "Diamalloy Steel" and "Made in U.S.A." forged into the front. The reverse is marked "Diamond Calk Horseshoe Co." and "Duluth, Minn." with the Diamond-Horseshoe logo. Both sides are also marked with the "4 In." nominal size.
The overall length is 4.3 inches, and the maximum opening is 0.5 inches.
The finish is chrome plating with polished faces.
Diamalloy 6 Inch Adjustable Wrench
![[Diamond Diamalloy 6 Inch Adjustable Wrench]](Photos/tools/diamond_adj_6in_wrench_diamalloy_f_cropped_inset.jpg)
Fig. 7 shows a Diamond Diamalloy 6 inch adjustable wrench, marked with "Forged Diamalloy Steel" and "Made in U.S.A." forged into the front. The reverse is marked "Diamond Calk Horseshoe Co." and "Duluth, Minn." with the Diamond-Horseshoe logo. Both sides are also marked with the "6 In." nominal size.
The overall length is 6.3 inches, and the maximum opening is 0.8 inches. The head thickness was measured at 0.39 inches.
The finish is chrome plating.
Diamalloy 8 Inch Adjustable Wrenches
The next two figures show examples of Diamalloy 8 inch wrenches.
![[Diamond Diamalloy 8 Inch Adjustable Wrench]](Photos/tools/diamond_adj_8in_wrench_diamalloy_ringed_f_cropped_inset2.jpg)
Fig. 8 shows an earlier Diamalloy 8 inch adjustable wrench, marked with "Forged Diamalloy Steel" and "Made in U.S.A." forged into the shank, with "Diamond Calk Horseshoe Co." and "Duluth, Minn." forged into the reverse. Both sides are also marked with the "8 In." nominal size.
The overall length is 8.1 inches, and the maximum opening is 1.0 inches. The head thickness was measured at 0.45 inches.
The finish is chrome plating with polished faces.
![[Diamond Diamalloy 8 Inch Adjustable Wrench]](Photos/tools/diamond_8in_adj_f_cropped_inset.jpg)
Fig. 9 shows a later Diamalloy 8 inch adjustable wrench, marked with "Diamalloy Alloy Steel" and "Forged in U.S.A." forged into the shank. The opposite side is marked "Diamond Tool and Horseshoe Co." and "Duluth, Minn." with the Diamond-Horseshoe logo.
The overall length is 8.1 inches, and the maximum opening is 0.9 inches. The head thickness was measured at 0.45 inches.
The finish is chrome plating with polished faces.
Note that the company name on this tool is now "Diamond Tool and Horseshoe" instead of "Diamond Calk Horseshoe", and a glance at the horseshoe logo shows that the diamond no longer has a calk.
Diamalloy 10 Inch Adjustable Wrenches
The next two figures show examples of the 10 inch Diamalloy model.
![[Diamond Diamalloy 10 Inch Adjustable Wrench]](Photos/tools/diamond_adj_10in_wrench_diamalloy_plain_f_cropped_inset2.jpg)
Fig. 10 shows a Diamalloy 10 inch adjustable wrench, marked with "Forged Diamalloy Steel" and "Made in U.S.A." forged into the shank, with "Diamond Calk Horseshoe Co." and "Duluth, Minn." forged into the reverse. Both sides are also marked with the "10 In." nominal size.
The overall length is 10.1 inches, and the maximum jaw opening is 1.2 inches. The maximum head thickness was measured at 0.58 inches.
The finish is plain steel.
The plain steel finish with the Diamalloy trademark suggests production during the 1942-1945 wartime years, when standard chrome-plated finishes were temporarily discontinued.
![[Diamond Diamalloy 10 Inch Adjustable Wrench]](Photos/tools/diamond_10in_wrench_adj_diamalloy_f_cropped_inset.jpg)
Fig. 11 shows a Diamalloy 10 inch adjustable wrench, marked with "Forged Diamalloy Steel" and "Made in U.S.A." forged into the front, with "Diamond Calk Horseshoe Co." and "Duluth, Minn." plus the Diamond-Horseshoe logo forged into the reverse. Both sides are also marked with the "10 In." nominal size.
The overall length is 10.1 inches, and the maximum opening is 1.2 inches. The maximum head thickness was measured at 0.57 inches.
The finish is chrome plating with polished faces.
Diamalloy 12 Inch Adjustable Wrench
![[Diamond 12 Inch Adjustable Wrench]](Photos/tools/diamond_12in_adj_f_cropped_inset.jpg)
Fig. 12 shows a Diamalloy 12 inch adjustable wrench, marked "Forged Steel" and "Made in U.S.A." with the Diamalloy logo in raised letters. The opposite side is marked "Diamond Calk Horseshoe Co." and "Duluth, Minn.", but without the usual Diamond-Horseshoe logo.
The overall length is 12.2 inches, and the maximum opening is 1.4 inches. The maximum head thickness was measured at 0.73 inches.
The finish is plain steel.
The plain steel finish with the Diamalloy trademark suggests production during the 1942-1945 wartime years, when standard chrome-plated finishes were temporarily discontinued.
Broached Hanging Holes
Sometime in the late 1930s or early 1940s Diamond added a new feature to its adjustable wrenches, a double-hex broached hanging hole. The broached hole was available for both the tool-steel and alloy (Diamalloy) models, but it's not known whether the new feature was present on all wrench models, or just as an optional feature.
Currently we're unsure of when the broached-hole models were first offered by Diamond. The Diamond wrenches illustrated in the Snap-On catalogs from 1927 and 1937 do not show a broached handle opening, and a Diamond catalog from the late 1940s also does not show broached openings. The only other manufacturer known to have offered adjustable wrenches with a broached hole was the J.P. Danielson Company, and its "Bet'R-Grip" brand wrenches were available with this feature from 1933 through 1947.
The next few figures will show examples of Diamond wrenches with broached hanging holes.
Tool Steel 6 Inch Adjustable Wrench with Broached Opening
![[Diamond 6 Inch Adjustable Wrench]](Photos/tools/diamond_adj_6in_wrench_broached_f_cropped_inset2.jpg)
Fig. 13 shows a Diamond 6 inch adjustable wrench with a broached hanging hole, marked with the Diamond logo, "Tool-Steel Drop-Forged", and "Made in U.S.A." forged into the front, with "Diamond Calk Horseshoe Co." and "Duluth, Minn." forged into the reverse. Both sides are also marked with the nominal size as "6" followed by a double-quote inch mark, and the hole is marked with its "1/2" size. Note that this wrench is not marked with the Diamond-Horseshoe logo, possibly due to insufficient space.
The overall length is 6.3 inches, and the maximum opening is 0.8 inches. The head thickness was measured at 0.46 inches.
The finish is plain steel.
The distinctive feature of this example is the 1/2 inch double-hex broached hanging hole, a feature also seen on J.P. Danielson "Bet'R-Grip" wrenches from the 1930s.
Tool Steel 8 Inch Adjustable Wrench with Broached Opening
![[Diamond 8 Inch Adjustable Wrench]](Photos/tools/diamond_adj_8in_wrench_toolsteel_broached_f_cropped_inset2.jpg)
Fig. 14 shows a Diamond 8 inch adjustable wrench with a broached hanging hole. The wrench is marked with the Diamond logo followed by "Tool-Steel Drop-Forged" and "Made in U.S.A." forged into the shank, with "Diamond Calk Horseshoe Co." and "Duluth, Minn." forged into the reverse. Both sides are also marked with the "8 In." nominal size, and the hole is marked with its "9/16" size.
The overall length is 8.1 inches, and the maximum opening is 0.9 inches. The head thickness was measured at 0.56 inches.
The finish is chrome plating.
Diamalloy 8 Inch Adjustable Wrench with Broached Opening
![[Diamond Diamalloy 8 Inch Adjustable Wrench]](Photos/tools/diamond_adj_8in_wrench_diamalloy_broached_f_cropped_inset2.jpg)
Fig. 15 shows a Diamalloy 8 inch adjustable wrench with a broached hanging hole, marked with "Forged Diamalloy Steel" and "Made in U.S.A." forged into the shank, with "Diamond Calk Horseshoe Co." and "Duluth, Minn." plus the Diamond-Horseshoe logo forged into the reverse. Both sides are also marked with the nominal size as "8" followed by a double-quote inch mark, and the hole is marked with its "9/16" size.
The overall length is 8.1 inches, and the maximum opening is 1.0 inches. The head thickness was measured at 0.47 inches.
The finish is chrome plating with polished faces.
Diamalloy 12 Inch Adjustable Wrench with Broached Opening
![[Diamond Diamalloy 12 Inch Adjustable Wrench]](Photos/tools/diamond_adj_12in_wrench_diamalloy_broached_f_cropped_inset2.jpg)
Fig. 16 shows a Diamalloy 12 inch adjustable wrench with a broached hanging hole, marked with "Forged Diamalloy Steel" and "Made in U.S.A." forged into the shank, with "Diamond Calk Horseshoe Co." and "Duluth, Minn." plus the Diamond-Horseshoe logo forged into the reverse. Both sides are also marked "12 In." for the nominal size, and the broached hole is marked "3/4" on the reverse.
The overall length is 12.2 inches, and the maximum opening is 1.4 inches. The head thickness was measured at 0.73 inches.
The finish is chrome plating with polished faces.
Later Production
In later years the Diamond adjustable wrenches were produced in a different design closely resembling the Crescent brand wrenches. This design can be easily recognized by the depressed panel of the handle, which extends all the way to the adjusting screw.
Diamond 10 Inch Wide Adjustable Wrench
![[Diamond 10 Inch Wide Opening Adjustable Wrench]](Photos/tools/diamond_10in_wrench_adj_wide_f_cropped.jpg)
Fig. 17 shows a later Diamond 10 inch wide opening adjustable wrench, marked with the Diamond logo plus "Wide Opening" and "No Hammering" forged into the shank, with "U.S.A." on the reverse (not shown).
The overall length is 10.0 inches. The jaws of this model open up to about 1.3 inches, compared to about 1.1 inches for a standard 10 inch wrench. The maximum head thickness was measured at 0.57 inches.
The finish is chrome plating with polished faces.
This example shows the different design used by later Diamond-brand wrenches, with the depressed panel extended all the way to the adjusting screw. (For a comparison with the Crescent design, see the Crescent Late Adjustable Wrench.)
Pliers and Other Tools
Diamond K36 6 Inch Combination Pliers
![[Diamond K36 6 Inch Combination Pliers]](Photos/tools/diamond_k36_pliers_combo_zinc_f_cropped_inset.jpg)
Fig. 18 shows a pair of Diamond K36 6 inch combination pliers, stamped "Duluth, USA" with the Diamond and Diamond-Horseshoe logos, and with "U.S.A." forged into the handles.
The overall length is 6.5 inches, and the finish is zinc plating.
Diamond Diamalloy H16 6 Inch Combination Pliers
In some of Diamond's later production the company name was dropped in favor of the Diamalloy logo, as the next example illustrates.
![[Diamond Diamalloy H16 6 Inch Combination Pliers]](Photos/tools/diamond_h16_pliers_cropped_inset.jpg)
Fig. 19 shows a pair of Diamalloy H16 6 inch combination pliers, stamped "Duluth, USA" with the Diamalloy and Diamond-Horseshoe logos, and with "Forged in U.S.A." forged into the handles.
The overall length is 6.5 inches, and the finish is chrome plating.
Diamond M26 6 Inch Bent Thin-Nose Combination Pliers
![[Diamond M26 6 Inch Bent Thin-Nose Combination Pliers]](Photos/tools/diamond_m26_pliers_combo_thin_bent_f_cropped_inset.jpg)
Fig. 20 shows a pair of Diamond M26 6 inch bent thin-nose combination pliers, stamped "Duluth USA" with the Diamond logo near the pivot, and with "Forged in U.S.A." forged into the handles.
The overall length is 6.6 inches, and the finish is chrome plating.
Diamond N18 8 Inch Thin-Nose Combination Pliers
![[Diamond N18 8 Inch Thin-Nose Combination Pliers]](Photos/tools/diamond_n18_pliers_combo_thin_plain_f_cropped_inset.jpg)
Fig. 21 shows a pair of Diamond N18 8 inch thin-nose combination pliers, stamped "Duluth USA" with the Diamond logo near the pivot, and with "Made in U.S.A." forged into the handles.
The overall length is 7.9 inches, and the finish is plain steel or black oxide.
Diamond Diamalloy DH18 "Handyboy" Combination Tool
![[Diamond Diamalloy DH18 Slip-Joint Handyboy Pliers]](Photos/tools/diamond_dh18_pliers_handyboy_cropped.jpg)
Fig. 22 shows an example of the popular "Handyboy" combination tool, a pair of Diamond DH18 slip-joint combination pliers with an adjustable wrench as one handle. The pliers are marked "Handyboy Duluth" with the Diamalloy trademark logo, and "U.S.A." is forged into one handle.
The overall length is 7.8 inches, and the finish is polished chrome.
This particular tool is relatively recent, having been purchased new in the 1980s.
Diamalloy SL56 6 Inch Lineman's Pliers
![[Diamond Diamalloy SL56 6 Inch Lineman's Pliers]](Photos/tools/diamond_sl56_pliers_linemans_diamalloy_f_cropped_inset.jpg)
Fig. 23 shows a pair of Diamalloy SL56 6 inch lineman's pliers, marked "Diamond Duluth" and "Made in U.S.A." near the pivot.
The overall length is 6.4 inches, and the finish is plain steel.
Diamalloy SN56 6 Inch Needlenose Pliers with Side Cutters
![[Diamond Diamalloy SN56 6 Inch Needlenose Pliers]](Photos/tools/diamond_sn56_pliers_needlenose_diamalloy_f_cropped_inset.jpg)
Fig. 24 shows a pair of Diamalloy SN56 6 inch needlenose pliers with side cutters, marked "Diamond Duluth" and "Made in U.S.A." near the pivot.
The overall length is 6.6 inches, and the finish is plain steel.
Diamalloy S56 6 Inch Diagonal Cutters
![[Diamond Diamalloy S56 6 Inch Diagonal Cutters]](Photos/tools/diamond_s56_pliers_diag_f_cropped_inset.jpg)
Fig. 25 shows a pair of Diamalloy S56 6 inch diagonal cutters, marked "Diamond Duluth" and "Made in U.S.A." near the pivot.
The overall length is 6.1 inches, and the finish is plain steel.
Diamalloy G57 7 Inch End Nippers
![[Diamond Diamalloy G57 7 Inch End Nippers]](Photos/tools/diamond_g57_pliers_nippers_diamalloy_f_cropped_inset.jpg)
Fig. 26 shows a pair of Diamalloy G57 7 inch end nippers, stamped with the Diamalloy logo and "Duluth" near the pivot.
The overall length is 7.3 inches, and the finish is plain steel.
Diamalloy HL18 8 Inch "Groove-Joint" Tongue-and-Groove Pliers
![[Diamond Diamalloy HL18 8 Inch Groove-Joint Tongue-and-Groove Pliers]](Photos/tools/diamond_hl18_pliers_groove_joint_f_cropped.jpg)
Fig. 27 shows a pair of Diamalloy HL18 8 inch tongue-and-groove pliers, stamped "Groove-Joint" and "Duluth, U.S.A." with the Diamond-Horseshoe logo.
The overall length is 8.0 inches, and the finish is chrome plating.
Diamalloy HL112 12 Inch "Groove-Joint" Tongue-and-Groove Pliers
![[Diamond Diamalloy HL112 12 Inch Groove-Joint Tongue-and-Groove Pliers]](Photos/tools/diamond_hl112_pliers_groove_joint_f_cropped.jpg)
Fig. 28 shows a pair of Diamalloy HL112 12 inch tongue-and-groove pliers, marked "Groove-Joint" and "Duluth, U.S.A." with the Diamalloy logo. (The markings are a bit difficult to read, but are located above and to the right of the pivot.)
The overall length ranges from 11.9 inches closed to 12.4 inches fully extended, and the finish is chrome plating.
Diamalloy HL18P 8 Inch "Groove-Joint" Tongue-and-Groove Pliers
In the early 1970s J.E. Swanstrom Jr. of Diamond Tool developed and patented a significant improvement for tongue-and-groove pliers. The next two figures show examples of this patent on pliers made for the Diamalloy brand, and as contract production for Blue Point.
![[Diamalloy HL18P 8 Inch Groove-Joint Tongue-and-Groove Pliers]](Photos/tools/diamond_hl18p_pliers_groove_joint_pat_f_cropped_inset2.jpg)
Fig. 29 shows a pair of Diamalloy HL18P 8 inch "Groove-Joint" tongue-and-groove pliers, stamped "U.S.A." with the Diamond-Horseshoe logo, and with a "Pat. 3739664" patent notice.
The overall length is 8.1 inches, and the finish is chrome plating with plastic hand grips.
The patent notice refers to patent #3,739,664, issued to J.E. Swanstrom Jr. in 1973. The patent describes a method of forging that allows the curved ribs of the pliers to be directly forged with an undercut edge. The upper left inset in the photograph shows the distinctly undercut edges of the ribs, which helps to hold the jaws of the pliers together under stress.
This patent was a significant improvement to the state of the art for tongue-and-groove pliers, as it combined the desirable undercut ribs described in Manning patent #2,640,381 with the forged ribs developed by Daugherty in patent #2,622,464.
Blue-Point HL112P 12 Inch Tongue-and-Groove Pliers
![[Blue-Point HL112P 12 Inch Tongue-and-Groove Pliers]](Photos/tools/bluepoint_hl112p_pliers_groovejoint_pat_f_cropped_inset.jpg)
Fig. 30 shows a pair of Blue-Point HL112P 12 inch tongue-and-groove pliers, marked "Made in U.S.A." with a "Pat. 3739664" patent notice.
The overall length ranges from 11.9 inches closed to 12.4 inches fully extended, and the finish is chrome plating.
The patent notice refers to patent #3,739,664, issued to J.E. Swanstrom Jr. in 1973. The patent describes a method of forging that allows the curved ribs of the pliers to be directly forged with an undercut edge. The upper inset in the photograph shows the distinctly undercut edges of the ribs, which helps to hold the jaws of the pliers together under stress.
Contract Production
In addition to producing tools for its own brands, Diamond Calk also provided contract manufacturing services to other companies, and the resulting tools were marked with the customer's brand. This section will show some examples of Diamond Calk production for other companies.
Montgomery Ward
Montgomery Ward sold tools under a number of brand names, including Riverside, Powr-Kraft, and Ward's Master Quality.
Ward's "Master Quality" 8 Inch Adjustable Wrench
![[Ward's Master Quality 8 Inch Adjustable Wrench]](Photos/tools/wards_adj_8in_wrench_mq_moly_broached_f_cropped_inset2.jpg)
Fig. 31 shows a Ward's "Master Quality" 8 inch adjustable wrench with a broached hanging hole, marked with "Wards Master Quality" and "Drop Forged" forged into the shank, with "Molybdenum Alloy" and "Made in U.S.A." forged into the reverse, along with the "9/16" size near the broached end.
The overall length is 8.1 inches, and the maximum opening is 1.0 inches. The head thickness was measured at 0.49 inches.
The finish is chrome plating with polished faces, with some loss due to wear.
This wrench is easily identified as Diamond Calk production by the construction and markings. We first note that this example is nearly identical in dimensions and features to the Diamalloy 8 Inch Wrench with Broached Opening shown in an earlier figure. The broached hanging hole in particular is an unusual feature for adjustable wrenches, with only two companies known to have made wrenches in this style: Diamond Calk Horseshoe and J.P. Danielson.
An example of the corresponding Danielson model can be seen as the Danielson "Vanadium" 8 Inch Adjustable Wrench in our article on J.P. Danielson. Although the Danielson wrench is similar to the example here, one major difference is the square jaw opening used by Danielson, instead of the hexagonal jaw found on Diamond Calk production.
Ward's "Master Quality" 6 Inch Adjustable Wrench
![[Ward's Master Quality 6 Inch Adjustable Wrench]](Photos/tools/wards_adj_6in_wrench_mq_moly_84-4701_f_cropped_inset2.jpg)
Fig. 32 shows a later Ward's "Master Quality" 6 inch adjustable wrench, marked with "Wards Master Quality" and "84-4701" forged into the shank, with "Molybdenum Alloy" plus "Drop Forged" and "Made in U.S.A." forged into the reverse.
The overall length is 6.2 inches, and the maximum opening is 0.8 inches. The head thickness was measured at 0.39 inches.
The finish is chrome plating with polished faces, with some loss due to wear.
References and Resources
Photographs and observations of particular tools are based on items in the Alloy Artifacts collection.
Catalog Coverage
Currently our catalog resources for Diamond include a "Condensed Catalog Supplement 8" from 1949, catalog W-83 from 1983, and catalog No. 700 from 1986. The latter two catalogs were issued after Diamond became a subsidiary of Triangle Tool.
The 1949 catalog supplement lists adjustable and auto wrenches, pliers and cutters, metal cutting snips, and crate opening tools. Included in the pliers section is a DH16 "Diamalloy Handiman" combination tool.
The two later catalogs are fairly similar and offer adjustable and auto wrenches, chain wrenches, a wide variety of pliers and cutters, screwdrivers, hammers, and other tools.
Diamond tools were available through various industrial suppliers, and the catalogs from these companies may have useful information for Diamond products.
Patent and Trademark Information
Patent information was obtained from the U.S. Patents and Trademarks Office (USPTO) web site at uspto.gov. Patent documents were obtained from sites offering free downloads, notably freepatentsonline.com.
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