As twertsy states , i.e. aa, known early sets do not have marked universals,
That was me, but thanks for confirming.
Oldtuleguy said:
including my #10 set which was largely unused and still had the original black paint on most pieces, including the universal.
I had forgotten you showed your Blackhawk #10 set in another thread, perhaps it was the Blackhawk thread itself, so now things are making much more sense to me.
So, you
also have a Blackhawk #8 set you're trying to complete, you recently found a loose
orphan universal joint, and without the benefit of it being found in a set, like the one in your Blackhawk #10 set, even though you were thinking it was probably a Blackhawk, by comparison, you started this thread to inquire if any other Mfgr's made a universal joint like that, to eliminate other possibilities, since it's unmarked.
See my post #8 above.
I really can't think of any other possibilities for a primitive universal joint with male and female connections other than Blackhawk. Remember that Blackhawk got into the game relatively late, at an interesting time of technology transition in the industry. In 1919, external drive pressed steel sockets - which they had never built, were waning, and forged heavy detachable sockets and handles were just beginning. The extensions in the early Blackhawk kits had one foot in the old style, too, with a socket with a female drive opening in it essentially hot-crimped or press-fit onto a 1/2-inch stock steel bar, rather than the extension made as a single forged piece of steel they would make in a few years hence.
EDIT: I'd have to do some work to actually verify this, but those early Blackhawk universals may actually be the first
ever 1/2-inch drive male-female universal joints, crudely hand-forged like the male-male unis in the old pressed steel socket sets, but advanced enough to use a female drive opening on the other end for a ratchet with a 1/2-inch drive male drive stud.