"DoN. Nichols" wrote in message
...
On 2014-08-18,
wrote:
...
Make your own. Probably something like drill rod, turn it to
fit into the clapper plate with a shoulder at the bottom to keep it
from
pulling through, and then mill a slot for it.
...
Good Luck,
DoN.

A Grade 5 bolt is a good starting point if you can find one with a
large enough shank. I'd buy one long enough that the tapped hole is in
the shank because rolling the bolt's threads work-hardens the steel
under them.

Fastenal has large square-headed setscrews.
-jsw