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 17181, Scotch-Brite Roloc Unitized Wheel Pack 987S, 2 in, 7000144150
3M 19765, Utility Cloth Sheet 314D, 9 in x 11 in P280 J-weight, 7000000353
3M 26106, PPS Series 2.0 Adapter, Type S22, 8 mm Male, 0.75 mm Thread, 7100135958
Insize 1120-3001WL, DIGITAL INSIDE GROOVE CALIPER, 1.97-12"/50-300mm, buit-in wireless, 6928640384844
3M 09215, Disc Pad Holder, 1-1/2 in 1/4 in Shank, 7000120559
3M 29611, 641WY 1/4" X 24", 100 Mesh Diamond Cloth Belt, 7010534832
Dynabrade 78582 1/4" Dia. x 1" W x 1/8" Center Hole, 180 Grit, 100/pack
3M 45095, Roloc Disc Pad TR, Medium 2 in 1/4-20 Internal, 7000045282
3M 26141, PPS Series 2.0 Adapter, Type S44, 3/8 Female, 19 Thread BSP, 7100158892
Norton 66254414832 - 3" X 1/4" X 1/4" Vortex Rapid Blend Unified Wheel, 5am U2305, 40 Each 