The Industrial 11/16-20 UN3A Thread Ring Gage is a GO/NO-GO inspection tool for verifying external 11/16-20 UN threads to Class 3A tolerances per ANSI B1.2 / ASME B1.2. Crafted from hardened tool steel and typically rated 60–62 HRC, it is designed for precision manufacturing, quality control, CNC machining, aerospace, and automotive production environments. Its specifications include thread size 11/16-20, UN thread series, Class 3A, and a GO/NO-GO ring gage design, with NIST-traceable calibration available. Manufactured by unknown/various manufacturers and available in new, used, and surplus inventory.
