Snerk.
1927.
The early catalogs really leaned into the mammalian allusion...
...reflecting the rationale in the "Snap-on Story" published for the 1960 annual shareholders' convention...
Snap-on was not the only American hand tool manufacturer to use the name. As I have noted previously, Milwaukee Tool and Forge used it for the same drive size in 1930...
...almost certainly because they had been making them for Snap-on. Me and
@Oldtuleguy and
@MR.X had some fun with that one on the MTF thread.
It may have been a coincidence. Meaning, someone at Snap-on or MTF or Motor Tool Specialty (their distributors) or all three may have independently arrived at the same name for the same reasons (its sleekness, etc). Then again, they may very well have appropriated it from Accles & Pollock. There is some evidence that they were acquainted with the industry in England, having listed the US licensed versions of the FAST-NUT wrenches in their early catalogs.