Key Pins

Key pins are hardened cylindrical dowel pins that fit into matching keyways on a shaft and its mounted component (e.g., gear, pulley, tumbler) in a tumbler set assembly. They transmit torque and rotational forces while maintaining precise alignment, ensuring synchronized operation. Typically press-fit or secured with set screws, they are critical for preventing slippage and maintaining positional accuracy in high-precision mechanical systems.

Key pins operate on the principle of positive mechanical interference. They are inserted into aligned keyways on both the shaft and the hub of a rotating component, creating a rigid connection that transfers torque and prevents relative rotational or axial movement. This ensures the component rotates exactly with the shaft, maintaining timing and alignment in the tumbler set mechanism.