Combine with a machine key to transmit torque to gears, sprockets, and other power transmission components.

Connect these internally threaded shafts directly to threaded components, or use a fastener to secure. They have a flat surface area that allows set screws to dig into the shaft for securely mounting gears, sprockets, and bearings.

Clip retaining rings into the grooves to separate and position gears, sprockets, and bearings.