This is a 5-piece set of step drills are ideal for electrical contractors, sheet metal workers, auto mechanics, & general contractors. They are ideal for drilling steel, copper, brass, aluminum and other thin metals. 
 
Specs
Black and Golf finish for professional look
High speed steel with Cobalt coating for long life & durability 
Two Flutes, which automatically deburs as you drill 
Tri-Flat shank for sure-grip 
Foam lined aluminum carrying case