EVOLUTION SHORT SERIES MAGNETIC DRILLING CUTTER KIT 25MM SET OF 6

6pc Cutter Kit 25mm Depth Cutters. Kit includes 12, 14, 16, 18, 20 & 22mm Cutters and Pilot Pins. Cyclone cutters are guaranteed to outperform annular cutters made out of HSS, Cobalt, or Tin Coated Cutters. The Tin Coating on HSS annular cutters increases the cost of the cutter but only enhances the cutter's appearance. HSS M-2 Annular Cutters can only be heat treated up to 64 RC before they become too brittle. Cobalt Annular cutters can only be heat treated up to 66 RC before they become too brittle. Cyclone Premium Annular Cutters can be heat treated up to 68 RC and they still have tempered hardness. A higher RC rating without brittleness means more holes cut per sharpening.