On Sat, 5 Sep 2009 19:46:56 -0700 (PDT), whit3rd
wrote:

On Sep 5, 6:17*pm, Steve Turner
wrote:

[bought bolts at Home Depot]
I get them home, and WTF? *I finally realize what is wrong, and now I'm
friggin' ****ed because the bolts are worthless for my application. *The
unthreaded portion of the shanks are a full 3/64" shy of their stated
diameters"!!! *Oh sure, the outside diameter of the threaded portion is
3/8", but the shanks aren't even close. *

Alas, that's normal. Unless you get 'shoulder bolts', the shank
diameter is not the controlled 3/8" you want, because the threads
weren't cut on a 3/8" blank, they were raised (rolled, it's called)
on a subsize blank. You can build up the shank with welding,
I suppose, or just roll a bit of sheet metal around
the shank. Or scrounge in decades-old assortments of
fasteners for an archaic example of what-you-expected.

Some high-strength fasteners will have the full shaft diameter,
perhaps,
because not all alloys are roll-able.

Shop with calipers.


And don't even think 3/4 inch ply is 3/4".