These shafts have keyways only on the ends, leaving a plain shaft in the center. Use the keyways with machine keys to transmit torque to gears, sprockets, and other keyed components. Use the middle of the shaft with bearings and other round-bore components.

A flat surface area 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.

Attach threaded accessories, such as mixer propellers and fan blades, to the end of these shafts.