TIMCO HSS Jobber Drill Bit, 5.5mm (HSSRR55) — a high-speed steel (HSS) general-purpose jobber drill bit for drilling through steel, aluminium, brass, wood, and plastics. The 5.5mm diameter is a commonly used size for pilot holes, clearance holes for M5 fixings, and general metalwork. Suitable for use in most corded and cordless drills.