RMT BlackGold 137° Heavy Duty Imperial Jobber Drill Bit.The Rocky Mountain Twist BlackGold imperial sized drill bit is a heavy-duty performance cutting tool. The RMT JH522 series drills more holes per tool, partly due to its aggressive web taper preventing breakage, and a shorter, stronger cutting lip. The heavy taper with a narrow tip ensures quick start machining without sacrificing the structure of the drill. These are excellent drills in high-speed cutting applications.
A precisely engineered drill bit, the BlackGold range allows for less torque and operator load. The ground split point penetrates the material surface on contact and prevents drill bit walking. Manufactured from Industrial-Grade National Aerospace Standard (NAS) High Speed Steel (HSS).
The JH522 series has a Tri-Flat Shank from 3/16” through ½”.
Rocky Mountain drill flutes are precision ground using the latest CNC technology at the foot of the Rocky’s in Montana. Ground precisely to tight quality standards, the flutes deliver superior cutting performance and accuracy.
Material ApplicationCarbon steels, alloy steels, stainless steels and strength alloys
SizesImperial drill diameters; including fractional drill sizes from 1/16” (.0625) to ½” (.5000), wire drill sizes from #1 (.2280) to #40 (.0980) and letter drill sizes from A (.2340) to Z (.4130).