What is the Higbee Cut on 2½ inch couplings?

• A. A feature to improve sealing
• B. To indicate thread size
• C. To align male and female couplings
• D. Blunt end on outer thread to prevent cross-threading

Answer: (D)

The Higbee cut is a small relief at the end of the male pipe thread that creates a blunt lead-in on the outer threads. This blunt end guides the threads into engagement as you start to screw the fittings together, reducing the chance of cross-threading and thread damage. It’s not about sealing (that comes from gaskets or tape) nor about indicating thread size. Its primary purpose is to make starting the thread easier and to prevent cross-threading, which is why it’s described as a blunt end on the outer thread.