For properly grinding 59° drill points for measuring drill tips. Rule and slide are made of steel with non-glare hard chrome finish. 6" rigid rule is calibrated in 8ths, 64ths, 32nds, and 64ths. Slide is calibrated in 32nds and 64ths. End clip is adjustable and removable. Versatile - can be used as rule, hook rule, try square, depth gage or caliper and for layouts.