Starrett Countersink Gages are offered in three different angles so that the gage sets on the angular side of the countersink, as opposed to a chamfer gage which sets on the top edge of the chamfer. FEATURES  Ground surfaces are of hardened tool steel  Indicators AGD design  90 Deg Angle  Directly reads the large diameter of the countersink  Includes set master ring  Includes set master ring SPECIFICATIONS  Made in America: Yes  Type: Countersink Gage  Range (mm): 0.5 - 4.3mm  Graduations (mm): 0.05mm  Dial Reading: For 90 Degree Countersinks