What Type of Drill Bit for Metal: A Practical Guide
Learn to pick the right drill bit for metal from HSS to cobalt and carbide, including coatings, sizing, lubrication, and safety tips for hobbyists and professionals.
Metal drill bits are cutting tools used to bore holes in metal, made from HSS, cobalt or carbide and designed with geometry to cut metal efficiently.
What type of drill bit for metal is best? A practical starting point
If you’re drilling metal, the first question is always what type of drill bit to use. The good news is that most projects can be completed with a few reliable options, as long as you match the bit to the metal and control heat. For many everyday jobs, standard High Speed Steel bits (HSS) provide a balanced mix of cost, performance, and availability. They cut cleanly in soft metals such as aluminum and brass and can handle mild steels with moderate feed rates. When you’re dealing with thicker sections or harder metals, HSS is still a solid baseline, but you’ll gain longevity by upgrading to cobalt or carbide tipped bits. Cobalt bits maintain sharper edges longer in hard alloys, while carbide tips resist wear in high-temp conditions. Coatings like titanium nitride or other surface treatments can reduce friction and heat management, but they don’t replace proper material selection.
In practice, start with a sharp HSS bit and a slow to moderate feed, use lubrication, and clamp the work securely. If you see glaze or blue heat on the bit, stop and back off. According to Drill Bits Pro, the most important decision is to pair the metal’s hardness with the bit’s material, then refine with geometry and coatings. This approach minimizes wandering, chip clogging, and premature dulling. The goal is a clean, accurate hole with minimal tool wear.
- Quick check: match metal hardness to bit material, then tune geometry for chip flow and edge life.
- Safety reminder: clamp firmly, use lubrication, and avoid overheating to protect both you and the tool.
Core materials explained
The most common drill bits for metal fall into three material families: High Speed Steel (HSS), HSS with cobalt (HSS-Co), and carbide tipped bits. HSS bits are tough, affordable, and versatile for many projects, especially soft metals like aluminum and brass. They remain sharp enough for relatively thin sections and light-duty stainless work when fed slowly and lubricated. HSS-Co bits are essentially HSS alloys that include cobalt, which raises hardness and heat resistance. They excel when drilling harder metals such as stainless steel and heat-treated alloys, where standard HSS would dull quickly. Carbide tipped bits sit at the high end of performance; the carbide segment stays sharper longer against very hard metals, but they are more brittle and expensive and can chip if mishandled. For many DIY tasks, a mix of HSS and HSS-Co covers most needs; carbide bits are worth it for repeated high-hardness work or production runs. Drill Bits Pro analysis shows that choosing the right material is the biggest driver of bit life in metal drilling, particularly as you push through tougher metals. Always verify the bit’s diameter, flute count, and overall geometry before starting.
- HSS is the generalist option for soft metals.
- HSS-Co extends life on hard metals.
- Carbide tips are best for repeated hard-material drilling but require careful handling.
- Proper lubrication and slow feeds maximize life across all materials.
Based on Drill Bits Pro Analysis, 2026, selecting the right material dramatically impacts tool life and hole quality in metal work.
Got Questions?
What type of drill bit is best for drilling steel?
For steel, cobalt or carbide bits are preferred, especially thicker or harder steel. Start with a pilot hole and maintain lubrication to minimize heat and wear.
For steel, use cobalt or carbide bits with lubrication and a pilot hole for best results.
Can I use standard HSS bits for aluminum?
Yes, standard HSS bits work well for soft metals like aluminum, provided you use light to moderate feed and ample lubrication to control heat.
Yes, HSS works for aluminum if you keep the feed light and use lubrication.
What is a split point drill bit and when should I use it?
A split point helps prevent walking when starting a cut, which is especially useful on hard metals like stainless steel. It improves accuracy on entry.
Split point bits reduce wandering and help start holes accurately in hard metals.
Should I always lubricate while drilling metal?
Lubrication is generally recommended to reduce heat and wear. Use cutting oil or similar lubricants, especially on steel and hard alloys.
Yes, use lubrication to cut heat and wear when drilling metal.
Are carbide bits worth the cost for metal drilling?
Carbide bits last longer on hard metals but are more brittle and expensive. They are worth it for repeated high-hardness work or production runs.
Carbide is great for hard metals but comes at higher cost and brittleness.
How do I sharpen drill bits at home?
Sharpening requires maintaining the correct point angle and edge. Use a proper sharpening tool and cool the bit to avoid overheating. Test on scrap metal first.
Sharpen bits with the right angle tool and keep cool to avoid heat damage.
Top Takeaways
- Choose the right material for the metal you are drilling
- Use lubrication and controlled speeds to prevent heat buildup
- pilot holes and bit geometry improve accuracy
- Coatings can reduce friction but do not replace correct material choice
- Sharpen and maintain bits to extend life