6 Best Drill Bits for Steel | Cuts 75 Holes Without Slowing Down

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Each bit delivers 75 holes through 1/4-inch steel before dulling — buyers report that consistency across all 29 sizes

The KENDO set earns its top spot because it gives you a full range of sizes that genuinely hold up on steel. Each bit uses M35 cobalt steel (a high-speed steel alloy with 5-percent cobalt) and a bronze steam surface treatment — this finish is not cosmetic; it helps the steel resist wear and keeps the cutting edge hard. The 135-degree split point (a notch ground into the tip) reduces the force you need to start the hole, which makes a real difference when you are drilling thick plate with a hand drill.

Owners mention drilling 75 holes in 1/4-inch cold rolled steel per bit with no performance loss or need for resharpening. That kind of consistency — every bit capable of that before any dulling — is what lifts this set above the rest. The metal index storage box keeps the 29 fractional sizes from 1/16 inch up to 1/2 inch organized and clearly labelled. Compared to the 3-piece 7/16 BECOLLO set below, KENDO gives you roughly ten times the number of bits for a premium-tier price; it is a different league of versatility.

One honest caveat: the box rack can be fiddly to set out and close, per a few owners, and it is not meant for hardened steel — the bits work great on cold rolled, mild, and stainless but will struggle with fully hardened plate.

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A belt-clip cup case sets this apart from the KENDO set — same M35 cobalt, more portable storage

CaRoller takes the same 29-piece M35 cobalt recipe — all the same fractional sizes from 1/16 inch up to 1/2 inch as the KENDO set — but adds an amber coating (a light surface treatment that helps resist corrosion) and a completely different storage approach. Instead of a flat metal index box, you get a round cup-type holder with a built-in clip that attaches to your tool belt. That is a real time-saver if you are working on steel beams or automotive frames and need to swap bits without walking back to a toolbox.

Reviewers point out that one bit drilled 30 holes in a steel I-beam before showing significant wear, and the set arrives with each bit coated in light oil to prevent rust in the case. On mild steel these bits eat through the work; on stainless steel owners note you need to go slow and use cutting oil (a lubricant that reduces friction at the cutting edge), and the bits will eventually dull after repeated stainless use. Compared to the KENDO set at a similar price point, CaRoller is slightly more compact for carrying but lacks the bronze steam surface — a minor trade-off on wear resistance.

The verdict from most owners: the bits stay sharp through several steel projects with no sharpening needed yet, and the case has survived being carried on a belt without breaking.

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A buyer drilled 80 holes in thin stainless steel with the first 11/16-inch bit and reported it was still sharp afterward

Most drill bit sets stop at 1/2 inch. If you need an 11/16-inch hole — the cutting diameter is 17.91 millimeters — for plumbing, electrical conduit, or a custom metal bracket, the Narwhal 3-pack is the right size for that job. Each bit has a 6-inch total length and a 3-inch flute length (the grooved part that carries chips out), so you have enough reach to go through thick material without the bit shank hitting the workpiece. The M35 cobalt steel (5-percent cobalt) and the 135-degree split point are the same proven combination found in the smaller sets above, just scaled up.

One reviewer noted drilling roughly 80 holes in thin stainless steel with the first bit and that it was still sharp and unbroken. Another noted it “absolutely ate through cast iron like it was plastic.” Compared to the 3-piece 7/16 BECOLLO set below, the Narwhal bits have a cutting diameter about 3.8 times larger — 17.91 millimeters versus 4.76 millimeters — so these are for heavy work that the smaller sets simply cannot physically do. The KENDO set, for instance, tops out at 1/2 inch; you would need this Narwhal pack for any hole larger than that.

The catch: these are dedicated large bits. If you need a range of sizes, you will still need a smaller set. The plastic case is tough but only holds three bits — it is fine for storage but not a daily carry system.

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The pilot-point tip starts on contact — no walking, no center punch, no frustration on mild steel

DEWALT’s DW1369 takes a different approach from the cobalt sets above. Instead of a hardened alloy, these bits are high-speed steel with a titanium nitride coating (a super-hard ceramic layer that reduces friction and keeps the bit cooler). The real differentiator here is the pilot-point tip geometry: a notch ground into the cutting edge that lets the bit start on contact without skidding across the surface. That “on contact” start is a genuine time-saver if you are drilling dozens of holes in sheet steel and want clean, round openings without a center punch.

The 29-piece set covers the same fractional sizes from 1/16 inch to 1/2 inch as the KENDO and CaRoller sets, and the metal storage case is much tougher than the plastic cases found on many competitor sets. Buyers report the bits are extremely sharp from the start and cut very clean holes in mild steel. However, the titanium nitride coating is not as heat-resistant as cobalt alloy — on hard stainless or thick plate, these bits will dull faster than an M35 set like the KENDO. Bits may break under very heavy use, though that is expected from a general-purpose set.

One recurring owner note: the plastic insert that holds the bits in the metal case has painted size markings that wear off over time, and the back row of bits is hard to read without pulling them out.

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A buyer drilled 11 holes through thick steel with these three bits — competitor bits had failed after just one hole

The BECOLLO set gives you three identical 7/16-inch cobalt bits (cutting diameter of 11.11 millimeters) manufactured to the ANSI B94-11M standard — an industry tolerance spec for drill dimensions. The fully ground processing (the cutting edges are ground rather than rolled) produces a smoother surface with less friction, so the bit cuts faster. The 135-degree split point helps self-centering on that tricky first bite into a steel surface.

Owners mention using these bits to drill through the leaf springs of an F150 — a notoriously hard material — and getting through with the right technique: low RPM and constant cutting oil. Another owner drilled 11 holes through thick steel with three bits, noting that a competitor’s bits had failed after just one hole. Compared to the Narwhal 11/16-inch bits above, these BECOLLO bits are narrower (11.11 mm vs 17.91 mm, a 3.8x difference) but suited to the same kind of heavy work — just at a smaller hole diameter.

The honest limitation: these struggled with hardened steel and some owners found they tended to “walk” slightly on the start without a center punch. They work well on mild steel but are not a magic bullet for fully hardened plate.

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Twenty M35 cobalt bits for less than the price of a single premium bit — and customers note they actually work on steel

If your main job is drilling 3/16-inch holes (cutting diameter 4.76 millimeters) in steel sheet or plate, the RCINDUS 20-pack offers the lowest per-bit cost in this lineup while still using real M35 cobalt steel with a 5-percent cobalt content. Each bit has a 135-degree split point for self-centering and the diameter accuracy is held within minus 0.03 millimeters — a tight enough tolerance that you will not get oversized holes.

One buyer drilled through a 1/8-inch steel plate and used a single bit for all 10 holes; that same bit drilled as well on the last hole as on the first. Another owner reported that the cheap 20-pack outperformed a single name-brand bit, drilling roughly 25 stripped screw heads before dulling. Compared to the BECOLLO 3-pack above, the RCINDUS set gives you almost seven times the number of bits — a 20-piece vs 3-piece gap — but only in one size, 3/16 inch. You are trading size variety for pure volume for that one size.

The trade-off is that you get just one diameter. If your project needs multiple hole sizes, you will need another set. The plastic storage case is basic but keeps the bits organized.