DeWalt HSS E Cobalt Drill Bits 4.8 mm (10 pcs) — high-speed steel cobalt drill set

DeWalt HSS E Cobalt Drill Bits 4.8 mm (10 pcs) are a set of high-speed steel drill bits with a cobalt alloy designed for drilling through hardened steels and other demanding metallic materials. The 4.8 mm diameter offers a versatile size for creating precise pilot holes or enlarging existing holes in metalworking and maintenance operations. Supplied in a bulk pack of ten, this set is intended for use with both drill presses and hand drills in professional and workshop environments.

Advantages

The cobalt-enriched high-speed steel composition increases heat resistance and extends cutting life compared with standard HSS bits. A ground point geometry ensures accurate centring and reduced walking on metal surfaces, while the robust construction maintains edge sharpness under high load. The set format provides consistent diameter across multiple pieces for repetitive tasks and quick replacement when bits wear out.

Suitable for

• Drilling hardened and alloy steels
• Metal fabrication and repair work
• Workshop and construction site drilling with drill presses or hand drills
• Maintenance and mechanical assembly tasks

Key specifications

• Material: high-speed steel with cobalt alloy
• Diameter: 4.8 mm
• Pack quantity: 10 pieces
• Intended use: drilling in hardened steels and other tough metals
• Compatibility: suitable for use in drill presses and hand-held drills

How to use

Select an appropriate drill speed and cutting fluid according to the metal being drilled. Secure the workpiece firmly in a vise or with clamps to prevent movement. Fit the 4.8 mm bit into the drill chuck and tighten securely. Begin drilling at a controlled speed, applying steady, even pressure; withdraw the bit periodically to clear chips and allow coolant to reach the cutting edge. For through holes, continue until the desired depth is reached; for blind holes, monitor depth to avoid breaking the bit.

Usage recommendations

Use cutting fluid or coolant to reduce heat and extend bit life when drilling stainless steels or other heat-sensitive alloys. Start with a centre punch or pilot mark for greater accuracy, and reduce speed as drill diameter increases or material hardness rises. Replace bits once wear or chipping affects drilling accuracy or causes excessive heat build-up.