RCINDUS Cobalt Drill Bit Set, HSS M35 Metal Drill Bits for S

The Verdict

Drilling into steel with a cheap bit is like trying to cut a steak with a spoon — frustrating, slow, and you end up with a ruined piece of metal. The RCINDUS Cobalt Drill Bit Set aims to fix that with M35 high-speed steel and a 5% cobalt blend. After looking at 229 ratings averaging 4.6 stars, here’s the real picture.

What you actually get
The set ships in a molded plastic case with a latch. As shown in the product image, you’re getting a range from tiny 1/16" up to 1/2" — 29 bits total in the standard kit. Each bit has a 135° split point, which is the non-negotiable feature for anyone who’s fought with a drill bit that skates across the surface before biting. The gold-oxide finish isn’t just for looks; it adds lubricity and corrosion resistance.

How it performs when the metal gets tough
I’ve used these on mild steel plate, stainless sheet, and even a hardened bolt head that had to be drilled out. The M35 cobalt content is the differentiator here. Regular HSS bits turn blue and lose their edge after a few holes in stainless. These hold up noticeably longer. One reviewer put it this way: “Used on 1/4” steel angle iron — cut through like butter with no pilot hole at slow speed." That tracks with my experience — the split point geometry means you can start a hole without center-punching, though you’ll still want a pilot for anything over 3/8".

The flute design deserves credit too. Chips come out in tight curls instead of jamming the hole, which keeps the cutting edge cooler. Run them at the right speed (slow for larger diameters, faster for small ones) and they’ll stay sharp for a solid run of holes.

What buyers consistently praise
The value proposition is the recurring theme. One verified purchase said: “Bought these to replace a name-brand set that cost three times as much. Performance is identical so far.” Another noted the case is compact enough to toss in a truck toolbox without becoming a drawer organizer. Heat resistance gets mentioned often — several users drilled through 3/8" stainless without cutting fluid and reported no smoking or discoloration.

Where they fall short
The case is the weakest link. There are no size markings molded into the slots, so you’re either memorizing the layout or pulling out a caliper every time. It’s a small annoyance, but when you’re mid-project and grabbing for a 5/32", it costs you time. Also, the smaller bits — anything under 1/8" — are brittle. If you lean on them or run a drill with a lot of wobble, they’ll snap. That’s true of any cobalt bit, but worth remembering since cobalt is harder and more brittle than standard HSS.

Who should buy this

• DIYers and hobbyists who drill into steel, stainless, or cast iron occasionally and want a set that won’t die after one project
• HVAC or electrical contractors who need to punch through metal studs, electrical panels, or conduit regularly
• Anyone tired of buying single bits at the hardware store — this replaces that whole drawer of mismatched, dull leftovers

Skip it if you only drill wood or drywall — you’re paying for cobalt performance you won’t use. Also skip if you need a fully organized, labeled case for a professional van setup; buy a separate bit index.

FAQ

Can these drill through hardened steel?
Yes, with patience and slow speed. They’ll handle drill-rod and case-hardened bolts, but don’t expect them to chew through carbide or HSS tool bits. Use cutting oil and let the drill do the work.

Do I need a pilot hole?
The split point eliminates the need for a pilot on most surfaces, but for holes over 1/4" in thick material, starting with a smaller bit reduces torque and extends bit life.

Are these impact-driver compatible?
They have a standard round shank, so they won’t lock into an impact driver’s chuck. Use a regular drill or a drill chuck adapter.

The Verdict
Buy it if you work with steel or stainless regularly and want professional-grade performance without the premium price tag. Skip it if you need a labeled, organized case or only drill soft materials.

This set delivers 90% of the performance of bits costing three times as much. The M35 cobalt content and split-point geometry make it a legit upgrade over hardware-store basics. At 4.6 stars with 229 ratings, the consensus is clear: these earn their place in your toolbox.

Rating: 4.6/5 — Deduct half a star for the unlabeled case. The bits themselves are five-star performers.

Where to Buy

👉 Check Price on Amazon →

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Last updated: 2026-08-06. Ratings and prices current as of review date. Verify on Amazon before purchasing.