Hss Step Sheet Metal Drill Bits 1, superior quality and durable in use 2,dependable performance 3,complete in specification Hss Step Sheet Metal Drill BitsSpecification:a.spiral flute; b.straight fluteCharicteristic:1. Good quality and favorable price;2. Excellent,timely after-sales service;3. Shortest delivery ;4. Automatic production lines of diamond tools;5. Keep the competition power in the ...