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 83980, Roloc Disc Pad TR, Extra Hard 4 in 5/8 -11 Internal, 7000119300
Insize 6315, MICROMETER MEASURING FORCE DETECTOR, 6928640351143
3M 14215, Roloc Disc Pad TS and TSM, Medium 3 in 1/4-20 Internal, 7000119310
Dynabrade 98272 1/2" NPT Female Plug
3M 03126, General Purpose Sanding Sponge CP040-6P, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100101532, 6/pack 