Milwaukee's line of step drill bits far surpasses the competition. With single cutting edge design, you will have more control and a cleaner finish. Made of high speed steel, these new step drill bits are durable and designed to drill through most metals. The black oxide finish prevents corrosion and has great capacity to work with drilling lubricants. The new speed start tip prevents bit walking and allows faster penetration. With laser etched markings you will always know your hole sizes...no guess work! Finally, the 1/4 in. hex shank allows for fast bit change in impact drivers and sure grip in chucks.