Carbide Drill Bits are an alloy of HSS steel and cobalt, making them durable, more heat-resistant than standard HSS, and cost-effective for drilling hard materials like stainless steel at moderate speeds. Carbide drill bits, made from tungsten carbide, are the hardest and most heat-resistant option, excelling in high-speed, high-accuracy, heavy-duty work with materials like hardened steel, cast iron, and composites, but are more brittle, expensive, and sensitive to rapid overheating. 

Cobalt Drill Bits

• Material:A high-speed steel (HSS) bit with added cobalt. 
• Best For:Hard materials such as stainless steel, cast iron, and other frictional metals where heat resistance is needed. 
• Pros:
  • Excellent heat resistance and wear resistance. 
  • More durable and less prone to chipping than HSS. 
  • Can be resharpened. 
  • Cost-effective for tough materials. 
• Cons:
  • Can become brittle and break if not used carefully or if dropped. 
  • Cannot operate at the extremely high speeds of carbide bits. 
  • Not ideal for the hardest or abrasive materials. 

Carbide Drill Bits

• Material:Made from tungsten carbide. 
• Best For:High-speed, high-accuracy tasks on the hardest materials, such as reinforced plastics, abrasive composites, and CNC operations. 
• Pros:
  • Extremely hard and durable, lasting longer in demanding applications. 
  • Superior heat resistance for high-speed drilling. 
  • Provides precision for long runs and repeat accuracy. 
• Cons:
  • Significantly more expensive than cobalt bits. 
  • More brittle and can crack if subjected to sudden temperature changes or heavy impacts. 
  • Difficult to resharpen. 

Key Takeaways

• Choose Cobalt for a practical, budget-friendly step up from HSS for drilling tough metals at higher speeds. 
• Choose Carbide for the most extreme conditions and materials, where the high price is justified by increased durability, speed, and precision in long-term use.