RCD manufactures a full line of crank bolts to fit your needs. These crank bolts are machined from 4340 steel and heat-treated for maximum strength and durability. Available in several lengths and flange diameters, with 7/16-20, 1/2-20 or 3/4-16 threads. All crank bolts have a 1.0" hex and a black oxide finish. Length measurements are from the head flange to end of threads.