C.R. LAURENCE CS8S CRL Weldon 11/32" Countersink for No. 8 Screws. CRL Weldon Countersinks are known for their high quality unique designs and outstanding performance. They cut chatterless finished holes in aluminum everytime. Smooth drilling action from a single cutting edge no matter what angle you cut at. The 1/4" (6.3 mm) shank diameter fits any 1/4" or 3/8" drill chuck.. Part Numbers Variations: CS8S