How do you torque a Nylon Insert Lock Nut? I have been in mechanical application for most of my life, we were required two torque wrenches one for breakaway (off) and a different one for installation with regular calibrations. Now most Outboard Prop companies sell a plastic nut wrench but the boat manufacturer requires a torque specification for installation of the nut for the prop, so what is the best installation procedure? I know that during spec jobs, lock nuts and or washers were not reused due to the fact that it was a spec job. I reuse nylon insert prop nuts just due to the price that a marina charges for parts, and use a torque wrench but do not over tighten. Basically I torque to spec back off the nut and then reset the nut until contact.