by: Matthew Viau on Sep 16, 2016
In some applications a blunt start thread (AKA a thread higbee) is helpful, or even necessary. Firefighting hoses use higbees to allow for easy coupling of the hose connections. The connections are marked with a groove where they should align for an easy thread start. No one needs a cross-threaded connector when they're fighting a fire. Pipes threaded for oil drilling often require a thread higbee. The oil drilling business is highly competitive and lost time from an expensive, cross-threaded pipe connection is unacceptable. Many of the go/no-go gauges used for checking threads have a higbee to help clear chips away from the thread and once again prevent cross threading.
TL;DR - Blunt start threads prevent cross threading.
An ACME thread with a blunt start (higbee)
An ACME thread with a chamfered start
Copyright © "this year" Villa Machine Associates Inc.
Powered by HTML5