$1.72
A hex-head flange screw with a serrated bearing face, this fastener locks against the joint as it tightens, the teeth under the flange biting into the surface to resist the vibration that backs an ordinary bolt out. The built-in flange spreads clamping load like an integrated washer, so no separate washer is needed.
Serrations under the flange bite into the joint surface as this hex-head flange screw is tightened, locking it against the vibration that backs an ordinary bolt out of its threads. The integral flange spreads clamping load across a wider bearing area much like a built-in washer, so the fastener needs no separate washer to seat cleanly and hold.
Combining a wrenchable hex head, a load-spreading flange, and a self-locking serrated face in one piece makes it a common choice on joints that see steady vibration and cannot be allowed to loosen in service. Installed fresh, it restores the original clamp and lock of the joint it secures.
Match the thread diameter and pitch, the length, and the grade to the screw being replaced, since a flange-lock screw has to thread fully and reach full clamp for the serrations to hold.
