Asimeto Plug Thread Gauge (Go/NoGo) - Imperial - Right Hand - ASMEB1.20.1-2013 - 1/4 x 18Asimeto Plug Thread Gauge (Go NoGo) in imperial sizes is a precision instrument for verifying internal thread accuracy to ASMEB1. 20. 1 2013. Designed for quality control teams in machining and manufacturing, this right hand gauge provides clear go no go results for the 1 4 x 18 thread form. Size: Imperial 1 4 x 18 thread gauge, engineered for standard internal thread checks. Go NoGo design: Integrated go and no go checks deliver quick, unambiguous