CMT 190.508.11B Solid Carbide Up/Downcut Spiral Flush Trim Bit 1/2"The CMT 190. 508. 11B is a Up Downcut Spiral Router Bit with Bearing Guide. Up downcut spiral bits are compression bits that cut upward and downward simultaneously for chip free faces on both sides ideal for CNC through cuts in plywood, MDF, and laminates. SPECIFICATIONS Diameter (D) 1 2" Cutting Height (I) 1 7 8" Cutting Height I1 5 8" Total Length (L) 4 1 2" Shank (S) 1 2" Number of Teeth 2 + 2 Product Type Up Downcut Spiral Router Bit with Bearing