Used for setting of measuring instruments like horizontal comparators, length measuring machines for ID checking, dial bore gauges etc. Made from oil hardening non shrinking gauge steel, hardened and tempered to 60-62 HRC Sub-zero treated at -80 °C for long term dimensional stability Actual dimensions duly etched Calibrated at 20 °C under Standards room condition against national/international traceable standards Certificate of calibration is provided along with each master traceable to national/international standards, certificate under NABL (as per ISO 17025) as per request Master Setting Rings also supplied in standard set consisting of sizes: Set 1: Ø4.0, Ø5.0, Ø6.0 & Ø8.0 mm Set 2: Ø10.0, Ø12.0, Ø16.0 , Ø20.0 & Ø25.0 mm Set also supplied as per customer’s requirement