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 5681, Disc Pad Holder 915, 5 in x 1/8 in x 3/8 in M14-2.0 Internal, 7000028500
3M 83980, Roloc Disc Pad TR, Extra Hard 4 in 5/8 -11 Internal, 7000119300
3M 27551, EMI Copper Foil Shielding Tape 1181, 1/2 in x 18 yd (12.70 mm x 16.5m), 7000132182
3M 5677, DISC PAD HOLDER 914, 4 IN X 1/8 IN X 3/8 IN M14-2.0 INTERNAL, 7010299278
3M 45099, Roloc Disc Pad TR, Medium 1-1/2 in 1/4-20 Internal, 7000045280 
