Blue-Groove point and cutting edge for faster chip removal. Double cutting spurs scribe the outside of the hole reducing breakout. 10\% larger shank for added durability.
#10 Countersink Tool Irwin$11.99
#10 Countersink$12.49
Aim n Flame Lighter$5.49
1-1/4 Spade Bit Irwin$6.49