ARP Head Bolt Insert Washer, 0.625" OD, 0.312" Insert ID, 0.380" Insert OD, Chromoly, Black Oxide, Set of 10

These handy washers are made to protect the top of holes from galling or collapsing around studs or bolts. They’re ideal for head bolt holes, mid-motor plates, or any other high-wear area that requires a washer. Easy to install by just oversizing hole and pressing in washer. ARP Insert Washers are fully CNC machined from premium thru-hardened 8740 stock