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 87449 Silver Depressed Center Grinding Wheel, T27 Quick Change, 9 in x 1/4 in x 5/8-11 Center Hub Thread, 7010409732, 20 per case
3M 01322, Stikit Gold Film Disc Roll, 6 in, P500 grade, 7010327903, 75 discs per roll
3M 26110, PPS Series 2.0 Adapter, Type S24, 1/4 Female, R-Angle 18
Thread NPS, Side Cup Mount, 7100135940 
