One of the biggest mistakes contractors, technicians, and even seasoned DIYers make is assuming any metal bit will do the job on stainless steel. Truth is, using the wrong bit doesn’t just slow down your job—it can destroy both the bit and the material. If you’re working with 304, 316, or 410 stainless steel, this guide will help you avoid expensive work-hardening failures—and choose the best industrial drill bits for your fabrication needs.
Why Stainless Steel is a Different Beast
Stainless steel is durable, corrosion-resistant, and looks clean—but it’s tough on tooling. Especially when drilling, improper technique causes friction and heat. That heat leads to work-hardening, making the steel even harder than it was, and nearly impossible to drill through without damaging the bit.
Key Fact: Standard HSS (High-Speed Steel) bits won’t cut it. You’ll burn them out fast.
You need the best industrial drill bits that are engineered for strength and heat resistance.
What You Actually Need: The Right Bit + The Right Technique
To effectively drill through stainless steel—and avoid heat-related failure—you’ll need three things:
A cobalt drill bit Cutting oil for lubrication The peck drilling technique (drill in short bursts)
Let’s break this down.
The Bit Breakdown: Which Ones Work and Why?
| Bit Type | Material | Best For | Point Angle | Notes |
| HSS (Basic) | High-Speed Steel | Light metals, plastic | 118° | Not suitable for stainless |
| Cobalt (M35/M42) | Cobalt alloy | Stainless Steel | 135° | Heat-resistant, stays sharper |
| Carbide | Tungsten Carbide | Production environments | 135°+ | Brittle, costly, high RPM only |
Cobalt bits—specifically M35 or M42—are the go-to for stainless steel. They stay cool under pressure and maintain edge strength. Opt for a 135° split-point tip to avoid walking and reduce pressure.
Real-World Use: MRO, HVAC, Plumbing, and Fabrication
In facility maintenance (MRO), field HVAC repairs, or plumbing installations, time is money. A wrong bit means time lost, overheating, and worn tools. Cobalt bits, paired with oil-based lubrication and peck drilling, allow clean cuts in stainless sink brackets, metal studs, or custom ductwork.
Whether you’re a local contractor or supplying a multinational crew, the demand for best industrial drill bits has grown. Stainless is now standard across many systems.
Pro Tip: Flute Design Matters
Use bits with wide flutes to remove chips quickly. Stainless produces sticky chips that clog easily, leading to overheating. Flutes with better chip clearance reduce the chance of jamming and improve drilling speed.
Which Grade of Stainless Steel Are You Working With?
- 304 Stainless: Most common—kitchen, HVAC, sinks
- 316 Stainless: Marine-grade—corrosion resistance
- 410 Stainless: Hardenable steel—used in fasteners, some valves
The bit you choose must match the steel’s toughness. Cobalt bits handle all three, but especially shine on 316, which is notoriously hard.
Still Using Standard Bits? That Could Cost You.
If you’re still drilling stainless steel with standard jobber bits or leftover HSS sets, you’re likely spending more in replacement costs and downtime. Choosing the right bit isn’t an upgrade—it’s a necessity for stainless work.
3 Quick Questions Contractors Ask Us – Answered
Q1: Do I really need cutting oil every time I drill stainless?
A: Absolutely. Stainless steel generates intense heat. Cutting oil dissipates heat and reduces bit wear. Skipping it cuts bit life in half—or worse.
Q2: What’s the benefit of a 135° point angle over 118°?
A: A 135° split-point penetrates metal faster with less force. It centers better and reduces walking. It’s a must-have when drilling into curved or hard surfaces like stainless pipe.
Q3: Can I use the same bit on mild steel and stainless?
A: Technically, yes—but expect faster wear. Cobalt bits work for both, but stainless needs a slower speed and more cooling. For everyday mild steel, HSS might do. For stainless, don’t risk it.
Looking to Stock Up?
If you’re planning to buy drill bit / metal cutting / jobber length / left hand cut, make sure you’re sourcing cobalt or equivalent-rated bits that are rated for stainless steel. Ask for specifics based on your application—don’t settle for generic!
Final Thought
When it comes to stainless fabrication—whether you’re working on HVAC installs, industrial piping, or commercial kitchens—bit failure is preventable. Use cobalt, slow your speed, add lubrication, and drill smart.
And remember, if you’re supplying or running a team, the best industrial drill bits aren’t a luxury—they’re a long-term asset.
Need help finding the right bits for your crew or inventory? Contact an expert industrial supply team—they know what works.
