ARP 150-2501 Harmonic Balancer Bolt Kit 12Point Head Diameter 5/8-18 Socket 5/8

As the crankshaft flexes and twists, the balancer absorbs incredible amounts of kinetic energy. To ensure that the balancer is locked in position, ARP has developed these ultra strong 200,000 psi bolts that let you exert maximum clamping force. Special features include 1/4? thick, wide area washer and an extra tall 12-point head that accepts a deep socket and eliminates the worry of stripping the head.
Square Drive Balancer Bolts
ARP offers a special version of its rugged 200,000 psi rated balancer bolt that can accept a standard 1/2? drive ratchet or breaker bar to facilitate rotating
the crank assembly.

1/2? square drive forged into bolt head, enabling the rotation
of an engine with any 1/2? drive tool
Made from heat-treated 8740 chrome moly steel with heavyduty
black oxide finish