19/32 and 25/32 socket ???

Anyway, as I was puttin' stuff into the drawer for 1/2" drive good, I got wiping off and rackin' up the old 1/2" sockets I bought when I was a kid in the early 70s. In the regular sockets, there's a 19/32" and in the deep wells a 25/32".

Was there a common use for these two sizes?

I'm thinkin' there musta been somethin' like that for them to be included in the set. Kinda like my closely-held, don't-get-lent-out 11/32" combination wrench for points work.

Any ideas?

A common example, for a bolt with a 3/8 inch diameter shank:

An SAE standard head would be 1 1/2 x 3/8 inch = 9/16 inch.

A Heavy standard head would be 9/16 inch + 1/8 inch.

Under both of these formulae, a bolt with a "odd sixteenths" shank diameter would have a "odd thirty-seconds" head.

For a bolt with a 5/16 inch shank, an SAE head would be 1 1/2 x 5/16 inch = 15/32 inch, and a Heavy head would be 15/32 + 1/8 inch = 19/32 inch.

For a bolt with a 7/16 inch shank, an SAE head would be 1 1/2 x 7/16 inch = 21/32 inch, and a Heavy head would be 21/32 inch + 1/8 inch = 25/32 inch.

As "odd sixteenths" bolt shank sizes faded out of common use in the World War II era, the "odd thirty-seconds" wrench sizes became less needed, and thus less common. Then, since the 5/16 bolt shank was the one "odd sixteenths" size remaining in common use, the bolt-and-nut makers phased out the "odd thirty-seconds" head-size steps in favor of sixteenth-inch increments.

But, for what it's worth, a wrench with a 19/32 inch opening is usually a fair stand-in for a 15 millimeter wrench.

I use the classic view so I can't look down below just now to see who it was, but somebody mentioned the heavy heads earlier.

Thanks!

Charles

Kent

'Preciate it.

KEH