The sliding head may be adjusted to any position along the rule and locked by a thumb nut
The head is beveled to 59° (the correct drill point angle), and is also graduated in 32nds along the 59° face for measuring the drill lips which should be of equal lengths
The hook rule has accurate, machine-divided graduations in 8ths, 16ths, quick-reading 32nds and 64ths
Hook is adjustable and can be shortened or extended on either side of the rule, and may also be removed if desired
Tool can also be used as a Plain Rule, Hook Rule, Depth Gage, and Slide Caliper
For quickly and accurately determining the correct drill point angle of 59° and the correct length of drill lips necessary for clean-cut drilling at maximum feeds and speeds
Meets or exceeds accuracy and performance requirements of national and international standards and are traceable to the National Institute of Standards and Technology.