Thread Profile Gauge External (Go & Nogo) Size - 39 X 3 Mm (Ring Gauge). Wear Limit - 0.5 Mm. Ref. Drg. No. W/Bd - 353 Material - Tool Steel/ Stainless Steel & Hardened Supply With Calibration Cert Ficate - Valid For 01 Year Issued From Lab Approved From Nabl Or Similar Accreditation Board. [ Warranty P Eriod: 30 Months After The Date Of Delivery ] ]