@d42jeep
Follow-up on Spec. W-47...
It does not appear anywhere else in the ASO catalog, and I am sure you noticed that in Class 41 (Hand Tools), it only appears with the socket wrenches. As you have already noted, it is not applied to all socket wrenches. Only those on page 23. There is a 1/4-drive set on page 24 that is Spec. 41-W-10 Type I, Class I, and there are 1/4-, 3/8-, and 1/2-drive sets on pages 24 and 25 classified as "light duty" or "medium duty" that are conspicuously not subject to the Spec. W-47, raising the spectre of its notoriety!
You'll be happy to see that
I did find it in my copy of Pitman's Aircraft Mechanic's Pocket Manual, but, unfortunately, only on the NAF 1109 (3/8-drive) series drawing, and, just like the ASO Class 41, only as a reference. Still, I think you'll find it VERY helpful.
See Pic 2, and see especially the notation at the lower left.
Between that notation, your hunch about dimensions, and your empirical observation on an OAL difference between 7/8" sockets marked 1110-12 and 7/8" sockets marked 1110-16, I think we can safely extrapolate that the apparently rather unforgiving "dimension limit" or
tolerance (+/- 1/32"!) of Spec. W-47 is indeed the source of the differences.
Interestingly, most of the 1109 tools (speeder, ratchet, hinge handle, sliding tee, and all the sockets and swivel sockets) are annotated with the symbol that indicates "standard stock." Only the tommy bar (1109-7) for the hinge handle and the universal joint (1109-9) do
not have that symbol, and I am reading that as meaning they have to meet Spec. W-47.
I also think that means that we can interpret all the tools in the "light duty" and "medium duty" sets in Class 41 to be analogous to "standard stock."
Oddly, the Pitman manual is a 3rd edition (1944), which is the same year the Class 41 in my ASO Catalog was published. One would think they would agree, but the manual obviously did not carry the Spec. W-47 through to the 1110 tools. It does have an annotation at the bottom that says the drawing is for stock purposes only, and directs readers to another drawing ("68272 ALT. 4", if you want to go fishing...) for manufacturing details. Why Pitman included the drawing with manufacturing details for the 1109 3/8-drive series and not the 1110 1/2-drive series (and why they included no drawing at all for the 1108 (1/4-drive) series) is a mystery and just our bad luck. But again, I think it's enough to confirm your suspicions. Maybe the 1st (1941) and 2nd (1942) editions would have more or different info.
All,
I intended to find a more generic NAF place to put this instead of the Plomb thread. NAF sockets and tools do show up from other mfgrs (Snap-on, Bonney, etc), but the other threads we have where NAF is the main topic are very specific to machines with USN and NAF tags, the NAF 1156-1 fastener chest I found and restored, the prewar NAF 399xxxx stock numbered tools that preceded the wartime 11XX-** stock numbers, or whatzits. It would lose its salience separated from Don's examples. My apologies for the esoteric mini-deep dive.