Hi Provincial,
Here is an excerpt from page 5 of the US Army Ordnance Supply Catalog, ORD 5, Standard Nomenclature List (SNL) J-4, dated March 1945. Your drag link bit is Federal Stock Number 41-B-644.
Background:
The ORD 5 lists every hand tool in the US Army Ordnance Dept inventory, individually. It also lists sets, including itemized contents. I am not going to provide all those scans, but the Ordnance Dept used many socket wrench sets during the war in a variety of square drives (1/4, 3/8, 1/2, and 3/4), sizes, and configurations. These socket sets were part of larger tool-sets (with other wrenches, machinists’ hammers, screwdrivers, pliers, etc). Many of the 3/8- and 1/2-inch square drive sets in the ORD 5 had at least one drag link bit in the set, some had a few. The General Mechanics Tool-Set (119 pieces), for example, had three (3) drag link bits – the 41-B-645 1/2-inch square drive set you see in my reference excerpt above. A few of the 3/8-inch drive socket sets in the Ordnance Supply catalog only had one drag link bit.
In every case, that bit was the 41-B-644. From that I would gather it to be a very popular (diverse) size for several vehicles. The US Army Ordnance Dept was responsible for the maintenance of all tracked and wheeled vehicles in the fleet after August 1942, when the Quartermaster Corps was relieved of that responsibility.
With all the Plomb “WF” (Wright Field, HQ and location of the contracting agency for the US Army Air Forces) and Wright “AC” (Air Corps”, which was part of the USAAF) tools in your socket set, I think it’s safe to identify it as a USAAF/Air Corps tool-set. The US Army Air Forces, including the Air Corps, was a separate branch during WWII. It did not become the Air Force until 1946. And, it did not belong to the Ordnance Department.
Unfortunately, I don’t have anything similar to the ORD 5 for the USAAF in terms of period references. But, note that the USAAF had many of the same vehicles (including jeeps, 1.5 ton trucks, and bigger prime movers, etc). And, many of us collecting GMTK and upper echelon Ordnance tools also collect USAAF tools, and I can tell you that USAAF TM 1-425, which was used for training, and several Technical Orders that we do have, strongly suggests that many of the tool-sets and tools were similar. Since the government mainly followed industry standards, and most of the common hand tools were in the Federal Standard Stock Catalog (that’s where the Ordnance Dept got Federal Stock Numbers from), it stands to reason the USAAF had a 3/8-inch drive socket set, and, that it had a 41-B-644 drag link bit in it.
I have seen or owned wartime drag link bits from Snap-On, Blackhawk, Thorsen, Bonney, Duro, New Britain, and Walden. Those all have shoulders on either side of the blade. The only drag link bit I have ever seen forged like the P&C and your unmarked bit (without any shoulders or very minimal shoulders) was made by Truth. And I believe the Truth drag link bits have grooves on the base.
Since we know for a fact that Plomb was filling “WF” orders with P&C tools (I have had P&C DBEs with WF- markings), it stands to even more reason that could very well be an unmarked wartime P&C drag link bit in your set.
