Rocky Mountain Twist 3G-OTH-195581 — Technical Specifications

The ROCKY MOUNTAIN TWIST Threaded Shank Drill Bit: #21 is a cobalt threaded-shank drill bit with a 0.1590-inch diameter and a 1/4"-28 thread size. It features a black oxide finish and conforms to NAS 965 Type D specification, with an overall length of 9/16 inch.