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 02140, Fibre Disc Backup Pad, TN Quick Change , 4-1/2 in x 5/8-11 Internal, 7000045746
3M 45094, Roloc Disc Pad TR, Soft 2 in 1/4-20 Internal, 7000045278 
