Here is a nice set of high-carbon steel (i.e. not alloy?)
stamped open-end wrenches marked "Aetna" with a cursive
logo. These have come up once before, I think, on this site,
where it was suggested that they might be promotional
items for Aetna Insurance (they're not, I think.) I have also seen
them mentioned on Garage Gazette, and on the Schwinn Bicycle
forum, but no one has ever been able to identify the company or
the date with any confidence.
Notes:
(1) these are quite thick and strong for this type of wrench.
(2) the largest wrench in the set (1" x 7/8") replaces
the center hole with a Prestolite key.
(3) the remaining wrenches in the set replace the
center hole with a set of American-Form fine thread
(re)threading dies, arranged thus:
5/8" x 3/4" wrench has die marked 3/8 - 24.
1/2" x 9/16" wrench has die marked 5/16 - 24
3/8" x 7/16" wrnech has die marked 1/4 - 28
1/4" x 5/16" wrench has die marked 3/16 - 32
The last is quite unusual, I think: though GTD still
sold dies for coarse-thread sub-1/4" fractional sizes
in 1944, it had stopped selling the fine-thread ones
in favor of machine-screw sizes.
(4) For dating purposes, I see that the sizes are all
marked according to opening size, not nominal bolt size,
which (wrench people correct me) usually dates things to
post-1920, right? But the odd 3/16" die suggests pre-war,
maybe? And the explicit designation "carbon steel" suggests
that alloy steels had arrived on the scene, else there
was no reason to distinguish a non-alloy tool steel wrench?
So maybe 1920-1940??
(5) NOT, I think a promotional item for Aetna Insurance;
the logo does not come close to matching any of those
listed here:
http://www.aetna.com/about-aetna-insurance/assets/documents/seals-logos-of-aetna.pdf(6) Do the fine threads suggest an automotive application?
