This Makita HSS TiN Metal Drill Bit Set is ideal for professional use as the drill bits have a titanium-nitride coating, this means that they produce minimal levels of friction and therefore reduces friction deposits, keeping the work area clean and tidy and not causing any damage or staining. The HSS construction ensures these drill bits are suitable for alloyed and non-alloyed steel. Included in this set is all in a organised carry case to help keep them organised. Features and Benefits: Sets of drills for metal Makita HSS-Tin Economy are made of high-speed steel HSS by rolling, followed by grinding and coating with titanium nitride. Designed for drilling holes in structural steel (normal and hardened), gray and forged cast iron, various types of plastic Titanium nitride coating increases wear resistance and drill life Reduced friction coefficient during drilling Increased drilling speed 135 � Split Point sharpening does not require center punching Small band width Reinforced working part of the drill Supplied in a convenient plastic case