Carriage bolt hole sizing
Carriage bolt hole sizing
(OP)
Hello all
Anybody famlilar with standard practices for sizing of a square clearance hole in steel plate for a carriage bolt?
for example, a 3/8 carriage bolt has a .388 SQR neck. Should the the punch for this be .030" oversized, similar to a standard bolt clearance hole?
Anybody famlilar with standard practices for sizing of a square clearance hole in steel plate for a carriage bolt?
for example, a 3/8 carriage bolt has a .388 SQR neck. Should the the punch for this be .030" oversized, similar to a standard bolt clearance hole?





RE: Carriage bolt hole sizing
Let's say, for example, I'm clamping pressure-treated 2x4's outdoors with a 3/8" carriage bolt: I can actually put the 3/8 carriage bolt into a 1/2 dia galvanized washer to spread the carriage bolt's head pressure out and avoid pulling the carriage bolt too far into the wood. The square of the carriage bolt grips hard enough into the hole of the oversized galv washer so the bolt doesn't turn, and the oversized washer prevents the bolt from pulling through.
But, if you don't have "soft" wood or are going into metal where the square needs to "bite" firmly into the material, then you need to broach a square hole. Gaps between the square head and the square hole need to be as small as practical to avoid rotation.
RE: Carriage bolt hole sizing
I assume you are talking about an oversize square hole.
RE: Carriage bolt hole sizing
RE: Carriage bolt hole sizing
B.E.
RE: Carriage bolt hole sizing
Mike Halloran
Pembroke Pines, FL, USA
RE: Carriage bolt hole sizing
B.E.