Best Drill Bits for Steel: A Practical Guide
Discover the best drill bits for steel and how to choose between carbide, cobalt, and HSS. This practical guide covers materials, speeds, lubrication, and real-world tips for clean, precise holes.
The best drill bit for steel is typically a carbide-tipped or cobalt-alloy bit, chosen for hardness and heat resistance. For most DIYers, a carbide-tipped bit in a mid-range set offers the best balance of longevity, sharpness, and price. If you’re on a budget, high-speed steel with a proper lubricant can still work well for mild steel.
Why the question matters: what is the best drill bit for steel
Drilling steel presents unique challenges: tendency to walk, heat buildup, and rapid edge dulling. If you want clean, accurate holes, you must pair the steel type with the right bit, proper speed, and adequate lubrication. So, what is the best drill bit for steel? In most scenarios, carbide-tipped bits or cobalt-alloy bits perform best because they resist softening and stay sharp longer under heat. For many DIYers, a carbide-tipped bit in a mid-range set strikes a strong balance between longevity, precision, and price. When you’re on a tight budget, high-speed steel (HSS) works with generous lubrication on mild steel, but expect more frequent sharpening and slower feeds. The key is to match the material, design, and technique to the job at hand. According to Drill Bits Pro, starting with a quality carbide-tipped bit set will unlock reliable holes across a wide range of steel thicknesses.
Carbide-tipped drill bits are the top general recommendation for steel projects, with cobalt for very hard alloys.
For most DIYers and professionals, carbide-tipped bits provide the best blend of durability and sharpness. If budget is a concern and you’re drilling mild steel, HSS with proper lubrication remains effective. For hardened steels, consider cobalt or carbide to minimize wear and heat-related damage.
Products
Carbide-Tipped Drill Bit Set
Premium • $40-120
High-Speed Steel (HSS) Drill Bit Set
Value • $15-40
HSS-Co All-Purpose Drill Bits
Mid-range • $25-60
Titanium-Coated Drill Bits
Budget+ • $10-30
Cobalt Alloy (M35) Drill Bits
Premium • $30-70
Carbide-Tipped Step Drill Bits Set
Premium • $35-90
Ranking
- 1
Best Overall: Carbide-Tipped Bits9.2/10
Outstanding durability and versatility across common steel grades.
- 2
Best Value: HSS-Co All-Purpose Bits8.8/10
Balanced performance and cost for routine steel projects.
- 3
Best for Hardened Steel: Cobalt Bits8.6/10
Top-tier heat resistance for tougher alloys.
- 4
Best All-Around Set: Titanium-Coated Bits8.2/10
Low friction with decent life, great for mixed jobs.
- 5
Most Versatile: Carbide-Tipped Step Bits7.9/10
Excellent for a range of hole sizes and stainless steel.
Got Questions?
What is the best material for drill bits when drilling steel?
Carbide-tipped and cobalt-alloy bits are typically best for steel, especially harder grades. Carbide offers long life in stainless and hardened steel, while cobalt provides excellent heat resistance for tough alloys. For budget projects, high-speed steel (HSS) with lubricant is acceptable for mild steel but will wear faster.
Carbide-tipped or cobalt bits are usually best for steel. If you’re on a budget, HSS with lubricant can work for mild steel, but you’ll need to sharpen more often.
Can HSS bits be used on stainless steel?
HSS bits can drill stainless steel, but they wear quickly due to work hardening and heat. For longer life and cleaner holes, carbide-tipped bits are preferred for stainless, followed by cobalt for very hard grades.
You can use HSS on stainless, but it wears faster. Carbide-tipped bits perform much better for stainless steel.
Do I need a pilot hole when drilling steel?
Yes, a small pilot hole helps guide the bit, reduces walking, and lowers heat generation. Start with a smaller bit, then progressively increase to the target size. This approach yields cleaner holes and protects the bit.
Always start with a pilot hole. It guides the bit and keeps the hole neat.
What speed should I use for drilling steel with carbide bits?
Use moderate speeds and steady feeds. Carbide bits tolerate higher speeds than HSS, but overheating still damages edges. In practice, start at a lower RPM and increase gradually while using lubrication.
Start slow and steady, then adjust as heat builds up.
Is cobalt better than carbide for drilling steel?
Carbide generally provides better wear resistance and longevity in many steels, while cobalt alloys excel at extreme heat and very hard steels. The best choice depends on the specific steel grade and hole size.
Carbide is usually the go-to for longevity, cobalt for extreme heat.
How should I lubricate steel drilling to prevent wear?
Apply a light cutting fluid or oil to reduce friction and carry away chips. Lubrication is especially important when using HSS or drilling stainless and hardened steels. Reapply as needed during longer drilling sessions.
Keep a steady trickle of lubricant on the bit. It helps cool things down and saves the edge.
Top Takeaways
- Choose carbide-tipped bits for durability on steel
- Use sharp bits and proper lubrication to minimize heat
- Match bit type to steel grade (mild, stainless, hardened)
- Balance budget and performance with a mid-range carbide or cobalt option