Thread runout is the measurement of the abruptness with which the buttress thread is terminated at the triangle end of the thread. A rapid pull-out of the cutting tool results in steep slope at the end of the thread. This causes high stress at the contact point when the coupling is made-up.
Buttress runout gages ensure proper thread pullout on runout type threads. Gagemaker buttress runout gages (BR-2000 Series) have standard 1″ and 2″ point spacing. Includes one contact point (TBR) and shoes.