I had several sets of these bolt made up a number of years ago. It was a
small group buy for me and a few other list members. I purchased bolts with
the correct grip from an aircraft hardware supplier. The bolts were too
long so they cut the threaded portion to length. We had the bolts made long
enough to allow a nut and lock washer to be installed on the engine
compartment side. This was per an old STOA tech tip authored by Tom Hall
IIRC. I can't remember who I bought the bolts from but I probably have it in
my archive.
Frank in Cloverdale
B9471116 sitting and waiting its turn for motor repair.
>Subject: RE: Front crossmember
>
>From the point of view of ultimate strength and number of cycles to
>failure,
>it's probably better to get a Grade 8 bolt that has the correct (or a
>little
>too short) length unthreaded portion, even if it's shorter than 5" overall,
>than it is to get the right overall length and then to use a die to put the
>extra threads onto the shank of the bolt. Real threads are rolled onto the
>shank, and the forging action orients the grain of the steel such that a
>rolled-thread bolt is much stronger and resistant to fatigue than one where
>the threads are cut into the shank. The sharp inner edges of the threads
>act
>as big stress risers.
>Theo
|