Irwin HSS Pro Drill Bits

The Irwin HSS Pro Drill Bit in 4mm diameter is supplied in a bulk pack of 10, making it an economical option for professionals who regularly use this popular general-purpose size. The 4mm diameter is widely used across construction, metalworking, and joinery applications, particularly for standard fixing holes and general fabrication work. Featuring high-quality HSS steel construction, this drill bit is engineered to withstand demanding professional use. The precision ground cutting edges enable fast drilling whilst ensuring perfect finishing, and the ground flute design provides maximum accuracy combined with fast chip removal for efficient, clean drilling.