Vouyar 6 Pcs M35 Cobalt Countersink Drill Bit Set for Metal with Case 82 Degree 1/4'' Hex Shank HSS 5 Flute Center Punch Tool Sets for Wood, Quick Change Bit 1/4” 5/16" 3/8” 1/2” 5/8” 3/4” - Amazon.com
Precision Twist Drill 041355 | #55 Diameter 1-5/8" OAL 135 Degree Cobalt High Speed Steel Bronze Screw Machine Length Drill Bit - All Industrial Tool Supply
5/8" Cobalt Heavy Duty Jobber Length Drill Bit, Drill America | D/ACOJ5/8 | DrillsandCutters.com
COUNTERSINK DRILL BIT SET FOR METAL - 5 PC HIGH SPEED STEEL WITH 5% COBALT HSS-Co M35 GRADE, SIZES 1/4", 3/8", 1/2", 5/8" & 3/4" - 5 FLUTES w/ 82 DEGREE -