Higbee cut

A Higbee cut is a specific modification added to the end of a screw thread to create a blunt start, replacing the sharp end typically found on unmodified threads. Named after its inventor Clinton Higbee, this feature reduces the risk of cross-threading when applied to both male and female threads. A blunt-start thread with a Higbee cut is also referred to as a convoluted thread.^[1]

Higbee cut on male thread

History

Clinton Higbee invented and patented the blunt start thread in 1891.^[2]

Common uses

Fire service

The Higbee cut is commonly used on the threads of fire hose couplings.^[3] The cut's presence and the thread's starting point are often marked on couplings to facilitate proper assembly.^[4]

Thread gauges

Gauging used to inspect machine threads often includes a Higbee cut.^[5]