UN Thread Ring Gage 7/8-9 UNC 7/8-14 UNF 7/8-20 UNEF 2A GO NOGO Gauge UNS RM 190.05 to RM 202.24RM 206.56
ISO Metric Thread Ring Gage M24 X 3 6g Threaded Gauges M24X3 2 1.5 1 0.75 0.5 mm RM 157.99 to RM 286.19RM 171.71