ARP 6421500 Black Oxide Steel 3/8-16 12-Point Bolts - Pack of 5 Bolts have a diameter of 3/8", a standard thread pitch of 16, an under head length of 1.500, and the wrenching is 3/8 Rated at 170,000 PSI, which is considerably stronger than Grade 8 hardware Manufactured from heat-treated 8740 chrome moly steel with a black oxide finish Heads are compact 12-point style Packaged on convenient 5-pack card