Cobalt Drill Bits

Cobalt drill bits are made from high-speed steel alloyed with cobalt. The cobalt addition increases hardness and heat resistance, making these bits suitable for drilling hard metals.

Cobalt Grades

M35 grade contains 5% cobalt and offers improved performance over standard HSS. M42 grade contains 8% cobalt and provides maximum heat resistance and hardness for the most demanding applications.

Hard Material Drilling

Cobalt bits excel at drilling stainless steel, cast iron, and other hard metals that generate significant heat during drilling. The increased heat resistance prevents softening of the cutting edge.

Brittleness Consideration

The increased hardness of cobalt bits comes with reduced toughness. Cobalt bits are more prone to chipping than standard HSS if subjected to lateral forces or interrupted cuts.

Cost Comparison

Cobalt bits cost more than standard HSS bits. The additional cost is justified when drilling hard materials that would quickly dull HSS bits.