The Best Drill Bit Sets for Hard Metals
SGS Tested & Trusted by Professionals Across the UK
- ✔ SGS Hardness Certified (66 Rockwell)
- ✔ 5% Cobalt M35 – Built for Hard Metals
- ✔ 100% Money-Back Guarantee
- ✔ Fast UK Delivery
Best Drill Bit Sets for Hard Metals – Buyer’s Guide UK
If you’re drilling into stainless steel, spring steel, or other tough alloys, you need more than just any drill bit — you need the best drill bit set for hard metals. That’s why professionals across the UK rely on our M35 cobalt drill bits.
Whether you’re a mechanic, engineer, metalworker, or DIYer, our 5% cobalt sets are designed to deliver outstanding performance on the toughest materials. Below, we break down the best sets based on size, use case, and what makes TTP HARD drills outperform the rest.
What Makes a Great Metal Drill Bit Set?
- Rockwell hardness above 60 – Essential for drilling hardened steel
- Cobalt content – 5% cobalt M35 bits handle heat and resist dulling
- Precision sizing – Full range in either metric or imperial increments
- Trusted by professionals – Mechanics, mobile fabricators, and engineers use these every day
| Category | Sizes Included | Best For | Buy |
|---|---|---|---|
| 19-Piece Metric Set | 1–10mm (0.5mm steps) | Everyday mechanics & installers |
Buy Now |
| 25-Piece Metric Set | 1–13mm (0.5mm steps) | Full workshop coverage |
Buy Now |
| All Metric Sizes | Singles & 10-packs (1–13mm) | Replace worn bits or bulk buy |
Buy Now |
| All Imperial Sizes | Singles, 21 & 29 sets (1/16″–1/2″) | Imperial projects & locksmith work |
Buy Now |
What Customers Say
“BEST METAL DRILL BITS I HAVE EVER USED”
These are by far the best metal drill bits I have ever used hands down. I hesitated to purchase these bits for a while because of the price but finally pulled the trigger and can say I was stupid for not buying them right away. If you’re thinking of buying these but are hesitant because of the price, do yourself a favour and get them — you will save time and money in the long run.
– Jodie Sdhlecher, ★★★★★
“DRILLING STAINLESS WITH 3MM & CUTTING PASTE”
I’d been having trouble drilling stainless steel, even with the “best” bits from the local hardware store. On an internet recommendation, I tried these. With a dab of cutting paste, these drills will go through stainless the way most drills cut through soft metal, and cost much less than those I was getting from the hardware store.
– Steven Eugene Raiguel, ★★★★★
Independent Review by DIY Mark
DIY Mark, a respected U.S. DIY YouTube creator, put our drill bits head-to-head against top U.S. brands in his video:
▶️ Watch “Drill America vs TTP HARD Drill Bits – Drilling Hard Metal” on YouTube »
Why Choose TTP HARD Cobalt Drill Bits?
Our bits are independently tested and certified by SIG Testing with a Rockwell hardness of 66 — higher than many premium brands. They’re M35 grade, built for repeated use on hard metal without dulling or snapping.
✔ Outperformed top U.S. brands in a head-to-head test by YouTube reviewer DIY Mark
✔ Trusted by mechanics, engineers, local authority workshops, and mobile repair professionals
FAQs – Cobalt Drill Bit Sets
What metals can your drill bit sets handle?
Our 5% cobalt M35 sets are designed for hard metals including stainless steel, cast iron, spring steel, structural steel, and other tough alloys.
Are these drill bits suitable for cordless drills?
Yes — they work perfectly in cordless drills, provided your drill has enough torque and a variable speed setting.
What’s the difference between the 19-piece and 25-piece metric sets?
Both use 0.5mm steps. The 25-piece set includes bits up to 13mm, offering more flexibility for larger holes.
Do you ship across the UK?
Yes — we offer fast UK-wide shipping, with most orders dispatched same or next day.
Are the bits tested or certified?
Yes — all our cobalt drill bits are SIG tested and certified with a Rockwell hardness of 66, making them ideal for industrial and heavy-duty use.
Can I use these bits for drilling stainless steel?
Absolutely. These cobalt bits are specifically designed to handle stainless steel, mild steel, and even tough materials like Hardox.
Why Choose TTP HARD Cobalt Drill Bit Sets?
If you’re drilling stainless steel, hardened bolts, spring steel or other tough alloys, not every drill bit will do the job. That’s why our SGS-tested M35 cobalt drill bits are trusted across the UK by mechanics, engineers, and installers.
- Built for hard metals – 5% cobalt M35 steel resists heat and stays sharper for longer.
- Independently tested – verified at 66 Rockwell hardness for maximum durability.
- Flexible options – choose compact 19-piece, full 25-piece, or individual metric and imperial sizes.
- Proven performance – outperformed top US brands in independent YouTube reviews.
Whether you need a complete drill bit set for hard metals or just want to replace worn sizes, our cobalt sets give you the precision, strength, and value professionals rely on every day.
Cutting Paste Makes Drilling Metal Easier. 
Dont forget to use metal cutting paste when drilling any metal. It will lubricate, reduce friction, and prolong the life of your valuable drill bits.