Sway-A-Way’s 8124 studs are press-in, heat treated alloy steel wheel studs, designed specifically for truck wheel hubs. Our studs are cold headed and have rolled threads for superior strength over machined studs. Sway-A-Way Truck Wheel Studs are 5/8” -18 x 3.81” long and have a nut starter lead to prevent cross threading and speed up wheel mounting. The 3.81 dimension is from under the head to the end of the part. The hole size should be reamed to .640″ for these press in studs. From under the head to the end of the thread is 3.00″.