Originally Posted by odpurple
Thanks Carlos, I didn't think they would work at all. Rule of thumb, it takes four threads of penetration to have full strength.
This is quite likely (probably) true for the 4-40 fasteners we're discussing here, but the rule of thumb generalized for ANY fastener is that they should be threaded in a distance to match the diameter of the fastener for maximum strength. For a 4-40 that distance is probably about 4 threads.
Scottrik