OTC 2492 Spot Weld Drill Bits are the best standard spotweld drill bits available. Engineered for use with high speed tools, and specially coated to resist dulling at high temperatures. Exclusive tempering process creates a hardened surface that holds that sharpcutting edge. The OTC 2492 Set includes 2 - 6mm x 50mm bits and 3 - 8mm x 50mm bits. (replacement packs available). When spotwelds need to be drilled, these are the bits you'll be glad you own....the 2492 5Pc Spotweld Drill Bit Set from OTC!