Features and Benefits: Size: 5/16″ Includes 3 in a pack Spring loaded pilot “pops” the slug from the cutter Low cost sheet metal hole-making When you don’t have a lot of holes to make BlaircuttersTM provide fast accurate holes in materials up to 3/16″ thick. BlaircuttersTM are annular cutting tools that cut around the edge of the hole and eject the center as a slug. Because they’re hollow there’s no dead zone as with twist drills. And unlike hole saws that rip and tear through the material they quickly give you a quality virtually burr-free hole.