Accuracy: ?2″.
To inspect protractor, taper gage, index plate, index head and goniometer, can also be used to set angle.
Made of special alloy steel, hardness HRC64, high stability, wear resistance and easy combination.
Can be combined to any angle with interval 6 seconds after combination (6″, 12″, 18″, … , 360?).

3M 15908, Scotch-Brite Roloc High Strength Disc, HS-DR, 2714175, A/O, Very Fine, TR, 3 in, 7010309326, 100 per case
Insize 6144, ACCESSORY SET FOR DIGITAL CALIPERS, 6928640380839
3M 16091, PPS Mix Ratio Inserts, Large (28 fl oz), 7000028411
3M Scotchkote Liquid Epoxy Coating Spray System HSS Mix Nozzle, RightAngle, 7000058900 