THIS IS A BENDIX UNC 2A THREAD RING GAUGE DESIGNED FOR PRECISE MEASUREMENT OF 1/2-13 SIZE THREADS. THE GAUGE FEATURES A THICKNESS OF 0.43 INCHES, WITH A GO PITCH DIAMETER (GOPD) OF 0.4485 AND A LO PITCH DIAMETER (LO PD) OF 0.4435. IT IS SUITABLE FOR GENERAL GAUGING APPLICATIONS REQUIRING THE VERIFICATION OF UNC 2A THREAD LIMITS.