Posted by David Sherman on Thursday, November 04, 2004 at 11:03PM :
In Reply to: what's up with this? posted by jim in n.y. on Thursday, November 04, 2004 at 7:26PM :
As far as I've seen almost all the bolts on almost all older military vehicles are SAE (fine, or UNF) thread. The reason is so they don't shake loose as easily. It can make it hard to get them out, though, without mangling the threads if they're rusty or dirty. When I swapped front bumpers on an M35, which are held on by a dozen or so 5/8" SAE bolts, very few were fit to re-use. With fine threads, it's also more important to get everything very clean before assembling, especially if precise torque is important.
I've heard that HMMWVs use mostly coarse (UNC) bolts and they have problems with them shaking loose.
Theoretically SAE bolts should also be stronger because the threads aren't cut as deep.
I'd say this is just another sign of the military heritage and good design of the ffpw.
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