INSIZE Standard Thread Ring Gages, GO - NO GO SetINSIZE Standard Thread Ring Gages, GO NO GO Set These Standard Thread Gages allow you to inspect the pitch diameter for threaded products. All stock Standard Thread Ring Gages are made to Class 2A per Standard ANSI B1. 2. A Manufacturer's Inspection Certificate is included with each gage. Each Standard Thread Ring Gage is marked with nominal size, class of fit and Go NO GO marking. Select Thread Size from Pull Down List.