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 77559, Cubitron II Hookit Cloth Disc 784F, 77559, 36+ to 120+, 5 in x NH, Die 500X, 7100232738
3M 11411, Roloc Disc 361F, 50 YF-weight, TR, 1 in, Die R100N, 7000045095
3M 25143, Scotch-Weld Threadlocker TL77, Red, 50 mL Bottle, 7100039225, 10/case 
