Nuts & bolts 101

[LMH]

Proper use of fasteners and build practices is utmost! Converting my Hurricane to IRS, where the IRS unit bolted on the frame, I enlarged the holes and welded in tubes for the mounting bolts to pass through. That allowed the bolts to be tightened to torque spec w/o squeezing or dimpling the sides of the box frame. It was a lot of work but I've seen "loose" parts on cars because of "get it together" build practices and poor workmanship. Safety and quality go hand in hand.
Larry

[xb-60]

If the fastener is threaded up to the head, it's a screw ....and a screw should never be used it a shear load application

Cheers,
Glen

[Jaydee]

Spring washers seemed like a good idea many years ago, but proofed to be so wrong. Under severe torque it can spread apart and loosen the nut. You won't see any manufacturer use them anymore. Just flat washers if any, and no lock nuts either. The best idea I've seen were 2 washers with opposite micro ramps that, if any vibration tried to undo the nut it would actually tighten itself.
I still like nyloc but never use a impact gun to tighten them.
JD

[ACHiPo]

Originally Posted by Jaydee

Spring washers seemed like a good idea many years ago, but proofed to be so wrong. Under severe torque it can spread apart and loosen the nut. You won't see any manufacturer use them anymore. Just flat washers if any, and no lock nuts either. The best idea I've seen were 2 washers with opposite micro ramps that, if any vibration tried to undo the nut it would actually tighten itself.
I still like nyloc but never use a impact gun to tighten them.
JD

JD,
I think you’re describing Nord-Lock washers—by far the best locking mechanism for high vibration and heat. They come in a variety materials for hostile applications.
Nord-Lock Group | Secure and Innovative Bolting Solutions