Drill bit MILWAUKEE HSS-G CO 5.5 mm — high-speed steel chromium-coated

MILWAUKEE HSS-G CO 5.5 mm is a high-speed steel drill bit with a chromium (CO) coating, engineered for reliable metal drilling and general-purpose workshop use. Its precise 5.5 mm diameter and HSS-G construction provide consistent hole accuracy and cutting performance for repair, fabrication and maintenance tasks. The chromium finish increases surface hardness and improves wear resistance, making the bit suitable for repeated use in handheld drills and drill presses.

Advantages

The chromium coating reduces friction and improves resistance to abrasion, helping maintain cutting geometry over longer periods. High-speed steel core delivers good toughness and heat resistance for drilling into a variety of ferrous and non-ferrous metals. The 5.5 mm nominal diameter ensures repeatable hole sizes for fitting fasteners or dowels, while compatibility with standard drill chucks allows quick tool changes.

Suitable for

• Drilling holes in steel and other common metals
• General workshop repair and maintenance
• Fabrication tasks where consistent 5.5 mm holes are required
• Use with hand-held electric drills and bench drill presses

Key specifications

• Material: high-speed steel (HSS-G)
• Coating: chromium (CO) finish for improved wear resistance
• Diameter: 5.5 mm nominal
• Tip geometry: standard twist drill profile for metalworking
• Suitable mounting: standard drill chucks for handheld drills and drill presses

How to use

Select an appropriate drilling speed for the material being worked—lower speeds for harder metals and higher speeds for softer materials—secure the workpiece and use proper clamping. Fit the 5.5 mm HSS-G CO bit into the drill chuck and tighten securely. For metal applications, apply steady pressure and allow the bit to cut without excessive force. Use cutting fluid or coolant when drilling harder metals or when prolonged drilling is required to extend tool life and improve chip evacuation.

Usage recommendations

For best results, start with a centre punch or pilot hole when precision is required, and maintain moderate drill speed with cutting fluid on steel to reduce heat and wear. Inspect the bit regularly for signs of wear or chipping and replace when cutting performance degrades.