Crank screws in large, heavy duty machinery, such as engines and CNC mills. A wide handle gives you maximum leverage, and a long shaft reaches into deep pockets. The shaft is permanently bonded to the handle for a secure hold that won't break under high torque. To prevent slipping, these T-handle keys are precision manufactured to tight tolerances for an exact fit. They're made of hardened steel or stainless steel to last a lifetime in your tool kit.