Generally, the motor shaft with a 1/2" diameter will be inserted in one end, and a shaft, or lead screw also measuring 1/2" in diameter will be inserted into the other end. The screws that clamp the shafts will be tightened. These steel clamping coupling are for use with high torque motors and high inertia when the motor is changing directions. 1/2" to 1/2" - (Rigid Coupling (Aluminum) - 1/2" bores at each end)
