Aibecy 4pcs HSS Cobalt Stepped Drill Bit Set

Nitride coated, has nice heat resistance, corrosion resistance and rust resistance. No need for a hole, can automatically deburr holes as you drill. Special step stucture, can drill different size of holes.

Working with water cooling, can effectively extend the service life of bit ...Nitride coated, has nice heat resistance, corrosion resistance and rust resistance. No need for a hole, can automatically deburr holes as you drill. Special step stucture, can drill different size of holes.

Working with water cooling, can effectively extend the service life of bit, drilling speed 250-400 recommended. Apply to thin iron plate, steel board, wood, aluminum, insulation panels, PVC sheet, ect. Specifications: Material: high speed steel Coated: nitride coated