For No. 10 Screws
Produce Smooth, Round Countersunk Holes Every Time
Fits Any 1/4" or 3/8" Drill Chuck
 
Cuts faster than standard countersinks, and leaves a finished hole every time. Smooth drilling action from single cutting edge prevents chatter and fluted edges. The 1/4" (6 mm) shank diameter fits any 1/4" or 3/8" (6 or 10 mm) drill chuck.