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?).

Insize 6318, CALIPER/MICROMETER GRINDING MACHINE (caliper grinding blocks are included), 6940561953862
Standard Abrasives 726003, A/O R6 Straight Precision Cartridge Roll, 3/8 in x 1-3/4 in x 1/4 in 80, 7100098775
Dynabrade 95821 Dynabrade Air Lube 10W/NR, 4oz Bottle
3M 07054, General Purpose Sanding Sponge CP-041-ESF, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101551 