Bosch HSS-Co Twist Drill Bit 4.2 mm, 75 mm (Working Length 43 mm)

This 1-piece Bosch HSS-Co twist drill bit, 4.2 mm diameter with a 75 mm overall length and 43 mm working length, is designed for continuous metalworking tasks. The cobalt-alloyed high-speed steel is intended for drilling into tough industrial workpieces. It can be used on cast iron, non-alloyed steel, and stainless steel. A standard twist geometry clears swarf efficiently from the shaft as the cut advances, and the bit fits both handheld rotary drivers and stationary benchtop drill stands. The metallurgical composition keeps the bit stable when drilling dense alloys.

The split-point tip starts the cut on centre, reducing bit wandering on smooth metal surfaces. Direct torque transfer from the chuck to the cutting edge keeps material removal consistent without slipping. A straight, controlled trajectory is straightforward to maintain across typical workshop setups. The profile prioritises rigidity to handle the loads generated by high-friction drilling. Precision machining keeps the flutes ejecting debris even at elevated operating temperatures. Penetration becomes predictable when the cutting edge is aligned correctly from the first rotation.

• 4.2 mm drill bit diameter produces accurately sized pilot holes or clearance holes for specific metal fasteners.
• 75 mm overall length sets the maximum reach of the tool during deeper drilling operations.
• 43 mm working length defines the practical penetration depth before the active cutting flutes end.
• Cylindrical shank allows the bit to grip firmly in standard three-jaw chucks without needing additional adapters.
• Stainless steel body colour reflects the raw manufacturing material and offers clear visual contrast against darker workpieces.