Yankee Hill Machine Crush Washer 1/2" AR-15 5.56/6.8 SPC/9mm

The Yankee Hill Machine Crush Washer is a precision shim designed to index and lock any 1/2"-28 threaded muzzle device on your AR-15 barrel. It is rated for use on barrels chambered in 5.56 NATO, 6.8 SPC, and 9mm Luger.

Manufactured from 12L14 steel, this crush washer is designed to deform under torque as the muzzle device is tightened against the barrel shoulder. Once crushed to spec, the washer conforms to the barrel face and provides a solid, repeatable seat that holds the orientation of flash hiders, muzzle brakes, compensators, or thread protectors through recoil and heat cycles.

This is the same OEM-style washer YHM uses on their own 5.56 barrels and muzzle accessories, and it fits the standard 1/2"-28 thread pattern common to most AR-15 barrels in the supported calibers. A low-cost consumable that should be replaced each time a muzzle device is removed and reinstalled to ensure proper timing and a clean clocking of ports, slots, or prongs.