Features and Benefits:�3-Flat Shank prevents bit from slipping in the chuck�Black Oxide Finish resists corrosion for longer life�High Speed Steel Make-up is ideal for cutting into stainless steel, aluminum, brass, copper, plastic and more�Laser Etched Markings for fast, easy hole size identification�Single Cutting Edge provides true round holes every time�Speed Start Tip starts fast and reduces the risk of bit walkingOur line of step drill bits far surpasses the competition. With our 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 3-flat shank on the largest bit prevents slipping while the 1/4 in. hex shank on the two smaller bits allows for fast bit change in impact drivers and sure grip in chucks.