Brand: Summit Racing Manufacturer's Part Number: SUM-900220 Part Type: Drill Bits Product Line: Summit Racing? Step-Drill Bits Summit Racing Part Number: SUM-900220 UPC: 190861051591 Drill Bit Material: High-speed steel Drill Bit Color: Titanium nitride Quantity: Sold as a set of 3. Notes: Set includes one 6-step bit (3/16 in. to 1/2 in.)， one 9-step bit (1/4 in. to 3/4 in.)， and one 13-step bit (1/8 in. to 1/2 in.). Drill Bit Quantity: 1 Drill Bit Style: Step Additional Information Step Drill Bit Size 1/4， 5/16， 3/8， 7/16， 1/2， 9/16， 5/8， 11/16， 3/4 in. 1/8， 5/32， 3/16， 7/32， 1/4， 9/32， 5/16， 11/32， 3/8， 13/32， 7/16， 15/32， 1/2 in. 3/16， 1/4， 5/16， 3/8， 7/16， 1/2 in. Summit Racing? Step-Drill Bits Summit Racing? Step-Drill bits optimize your drilling! Our drill bits use a stepped， single cutting-edge design to penetrate sheet materials more smoothly than traditional twist-type drill bits. These bits are designed to eliminate the need for center punch holes， greatly reduce drill vibration and chatter， and automatically deburr the hole as it's drilled. They will work on plastic， metal， and fiberglass up to 1/8 in. thick.