Proform's Crankshaft Turning Nut and Balancer Bolts were designed for rotating an engine hassle-free. Built as a heavy-duty model, crankshaft turning nut and bolt are manufactured from high-quality Grade 8 steel with a durable black-oxide finish. By easily installing through the harmonic balancer, a turning nut and bolt will securely fasten the balancer onto the crankshaft, while providing a turning nut that is ready to rotate an engine's crankshaft when necessary.