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 55694, Stikit Film Disc w/Tab 375L, P180, 5 in x NH, Die 500X, 7100106554, 250 per case
Dynabrade 78318 2" Dia. x 1" W x 1/4" Shank, Very Fine, NWN DynaBrite Wheel, 10/pack
3M 20360, Scotch-Weld Epoxy Adhesive 2216, Gray, Part B, 5 Gallon Drum (Pail), 7000046360
Dynabrade 22091 2-3/4" x 8" Hand Sanding Block
3M 22392, Roloc Disc 361F, 24 YF-weight, TR, 3 in, Die R300V, 7000045090
Dynabrade 14010 Dynafile Abrasive Belt Tool Versatility Kit
3M 26017, PPS Series 2.0 Adapter, Type S10, 1/4 Female, R-Angle 19
Thread BSP for Side Cup Mount, 7100135927 
