Nylon Lock Nuts are an excellent value prevailing torque lock nut consisting of a metal body with a nylon locking collar built into the top of the nut. Its nylon compression brings the nut and bolt thread flanks into firm metal-to-metal contact. It provides constant, uniform locking grip at any position on a bolt when the collar is in full engagement. Nylon Lock Nuts are reusable due to the "Elastic Memory" of the nylon.