SCHNAP Logo

Making Trade Life Easy!

Cobalt Drill Bits

31/10/2025
by Rick Coleman
Cobalt Drill Bits

G'day! We've all been there. You're in the shed or on the worksite, trying to drill a hole in a bit of hard steel – maybe a ute tray, a stainless steel bracket, or a thick metal post. You grab your standard black High-Speed Steel (HSS) drill bit, give it a burl, and... screeeech. You get a bit of smoke, a lot of noise, and a drill bit that's now as blunt as a brick.

It's a fair dinkum frustrating experience. The truth is, your standard drill bit just isn't cut out for that kind of hard yakka. When you're tackling tough, abrasive metals, you need to bring in the heavy hitter: the cobalt drill bit.

Cobalt vs. Standard HSS Bits: What's the Real Difference?

This is the most important thing to get your head around.

  • A standard HSS bit (or even those gold-coloured 'titanium coated' ones) is just a steel bit with a very thin, hard coating on the outside. As soon as that coating wears off – which it does, quickly, on hard metal – the bit is knackered.
  • A cobalt drill bit is a completely different beast. It's not coated. Instead, it's a solid alloy. The cobalt (usually 5% - 8%) is mixed right through the entire steel bit.

This is a massive advantage. It means the bit has incredible hardness and, most importantly, extreme heat resistance all the way to its core. Even as the bit wears down and you resharpen it, that tough, cobalt-infused steel is still there, ready to cut.

When Should You Use a Cobalt Drill Bit?

Cobalt drill bits are a specialist tool for a specialist job: drilling into very hard or abrasive metals. They are the go-to for:

  • Stainless Steel: This is their number one job. Stainless steel is notoriously tough and will destroy a standard HSS bit. A cobalt bit is the right tool for the job.
  • Hardened Steel: Like a broken bolt you need to drill out.
  • Cast Iron.
  • High-Tensile Steel and other tough alloys.
  • Repetitive Drilling: For any tradie who has to drill hundreds of holes in metal, a cobalt bit will last a hell of a lot longer, saving time and money in the long run.

Don't use them on timber or plasterboard, mate. It's a waste of a good bit, and they can be more brittle than standard HSS bits, making them more likely to snap if you're not careful.

How to Use Cobalt Drill Bits Like a Pro (and Not Wreck 'Em)

These bits are tough, but they're also brittle. You can't just go at it like a bull at a gate. To make your expensive new bit last, you must follow these rules:

  1. SLOW AND STEADY WINS THE RACE: This is the golden rule. You must run your drill at a slow speed. We're talking slow. Too much speed = too much heat, and even a cobalt bit can be killed by excessive heat.
  2. USE A LUBRICANT (NON-NEGOTIABLE): For drilling hard metal, you need to use a cutting fluid or lubricant. It keeps the bit and the workpiece cool and clears the swarf (metal chips). This makes the bit last so much longer.
  3. FIRM, STEADY PRESSURE: Don't be a galah – let the bit do the work. Apply firm, consistent pressure. If you see smoke, you're either pushing too hard or spinning way too fast (or both!).
  4. USE A DRILL PRESS: If you've got one, a drill press is your best mate for this job. It gives you far better control over your speed and pressure.

The Right Tools for a Professional Job

Investing in a premium tool like a set of cobalt drill bits is the mark of a true professional or a serious DIYer. It shows a commitment to using the right, high-quality gear to do the job properly, safely, and efficiently.

That same "no-compromise" attitude is even more critical when it comes to electrical work. A licensed electrician knows that a safe, reliable, and compliant installation depends entirely on the quality of the components they install. While a cobalt bit cuts the perfect hole in a metal enclosure, the gear that gets fitted into it has to be top-notch.

This is why qualified professionals source their components from trusted, trade-quality suppliers like Schnap Electric Products. Schnap Electric is a leading Australian supplier of the professional-grade electrical components that tradies rely on. From the durable, IP-rated metal enclosures and switchboards that might need drilling, to the high-quality circuit breakers, compliant terminals, and cable glands that get installed, they provide the gear that ensures an installation is safe, secure, and built to last. For a job that's professional from the tool to the terminal, the pros use quality gear from a supplier like Schnap Electric.