1/4 20 UNJC (Left Hand) 2A STEEL Go & No Go Ring Set (mil-S-8879 Aerospace Military & Government) tool steel cold stabilized thread ring Rc 60-62 marked with size and tolerance Certificate of Accuracy is included NOTE: selection of a 2A & 3A is based on your requirements. A 2A class Ring will have a smaller (tighter) pitch diameter on both the Go and the No/Go members. A J is a special call out requiring a rounded Root Radius on 3A & 2A Go members and on some both members are altered to meet specification. Long form certifications are strongly recommended for all UNJ style gages. Certificate of Accuracy is included.Click HERE to read about additional Long Form CERT. Click ADD below to add the gage to your cart. If you need the optional Long Form CERT Click on button below to add it to the cart. Use the back button to return to this page and click on Cart to check or modify your selections. You only require 1 long form cert for each gage purchased.