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
Dynabrade 78103 2" Dia. x 36 Grit Premium Ceramic Non-Vacuum DynaCut Locking-Type Disc, 25/pack
3M 09555, Scotch-Brite EXL Deburring Wheel, XL-WL, 8S Fine, 12 in x 2 in x 5 in, 7000148257
3M 07056, Drywall Sanding Sponge CP-042, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100101555 