Titanium Nitride Coating resists heat and friction, extending the cutting edge life up to 6 times that of other high-speed step drill bits. Made from premium high-speed steel for increased durability. 135-degree split-point tip starts drilling immediately with less force and eliminates "walking" across the work surface. Rubber over-molded case has automatic indexing for easy bit access and identification. Removable cartridges are easy to carry to and from worksite.