Vermont Metric Thread Ring Gage Set, GO/NOGO Vermont's Thread Gages allow you to inspect the pitch diameter for threaded products. All stock Thread Ring Gages are made to Class X tolerances per ASME B1.16M (Metric Series Screw Threads). A Certificate of Accuracy is included with each gage. Each Metric Thread Ring Gage is marked with nominal size, class of fit and pitch diameters. Features include... M8.0x1.25 6g Threads GO and NO GO Set Certificate of Accuracy included Made from Tool Steel, 60/62 Rc. Specifications include... GO Gage Length: 8.7mm NO GO Gage Length: 8.7mm GO Pitch Diameter: 7.160mm NO GO Pitch Diameter: 7.042mm