Key takeaways
- Pro: Widest size coverage in this roundup, eliminating the need for a second set
- Pro: Consistent M35 grade across all bits, not just the popular sizes
- Con: Highest upfront cost; overkill if you only drill a few common hole sizes
What's inside
Drilling stainless steel is one of the most frustrating tasks a metalworker can face. The alloy work-hardens under heat, meaning a dull bit or slow speed turns your hole into a glazed, impossible-to-pierce surface. Bits that handle mild steel often burn up in seconds on 304 or 316, leaving you with a ruined workpiece and a spent drill bit.
The best drill bits for stainless steel share a few defining traits: high cobalt content (M35 grade is the practical standard), aggressive point geometry that bites without skating, and enough rigidity to resist deflection under the high pressure stainless demands. Coating matters less than substrate quality here — titanium nitride helps on wood and plastic but adds little on hardened metal. The eight sets below range from under ten dollars to just over sixty, and the right choice depends entirely on how often you cut stainless, what sizes you need, and whether you work in open bench space or tight, confined areas.
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Quick Picks
| Product | Best for | Price |
|---|---|---|
| Sinyeenglon 99Pcs M35 Cobalt | Full-size range in one case | $61.49 |
| BOSCH CO14B 14-Piece Cobalt | Trusted brand at a fair price | $46.99 |
| MACXCOIP 13Pcs M35 Cobalt | Tightest budget entry | $9.98 |
| 5PCS M35 Hex Shank Stubby Set | Impact drivers and tight quarters | $20.99 |
| MACXCOIP 29Pcs M35 Cobalt | Mid-range coverage without overspend | $57.98 |
| Crosstar 21Pcs Three-Flute M35 | Fast material removal on thick stock | $47.99 |
| GMTOOLS 15Pcs M35 Cobalt | Indexed storage on a budget | $16.99 |
| DEWALT DW1361 21 Pc. TiN Coated | Multi-material drilling beyond steel | $26.98 |
How We Picked
We compared published specifications — cobalt grade, size range, point geometry, shank type, and coating — against owner-reported performance on stainless specifically. The four criteria that separated the field: substrate quality (M35 cobalt outperforms plain HSS by a wide margin on hardened metal), price per bit across the full size range, whether the geometry is designed for aggressive self-starting in tough alloys, and the practicality of the included storage. A set with a poorly organized case or inconsistent sizing tolerances loses to a smaller set with better quality control.
The 8 Best Drill Bits For Stainless Steel in 2026
Sinyeenglon 99Pcs M35 Cobalt Set
This is the buy-it-once option for a shop that cuts stainless regularly and needs every size from 1/16″ to 3/8″ without hunting through drawers. The M35 cobalt substrate handles 304 and 316 without the rapid edge degradation you get from standard HSS, and the plastic index case keeps 99 bits organized rather than jumbled.
- Pro: Widest size coverage in this roundup, eliminating the need for a second set
- Pro: Consistent M35 grade across all bits, not just the popular sizes
- Con: Highest upfront cost; overkill if you only drill a few common hole sizes
Skip this if your stainless work is occasional and limited to one or two diameters — a smaller set saves real money.
BOSCH CO14B 14-Piece Cobalt Set
BOSCH brings name-brand consistency to a category flooded with no-name imports. Owners report tight size tolerances and reliable geometry out of the box, which matters when you need a clean hole without reaming. The cobalt content is appropriate for stainless at moderate speeds with cutting fluid.
- Pro: Brand-backed quality control reduces the gamble on inconsistent sizing
- Pro: Compact case fits a tool bag or bench drawer easily
- Con: Only 14 pieces — you will likely need a companion set for uncommon sizes
Skip this if you need sizes below 1/8″ or above 1/4″ regularly; the range is narrower than competitors at similar prices.
MACXCOIP 13Pcs M35 Cobalt Set
At under ten dollars, this is the cheapest path to cobalt-grade bits sized for common stainless work from 1/16″ to 1/4″. For hobbyists drilling occasional brackets, fittings, or sheet metal, it delivers the critical M35 substrate without a premium. Owner feedback generally supports it for light-duty use.
- Pro: Lowest entry price for genuine M35 cobalt construction
- Pro: Covers the most frequently used small diameters for thin stainless
- Con: Size range stops at 1/4″, limiting it to lighter gauge work
Skip this if you drill holes larger than 1/4″ or work with stock thicker than a few millimeters — the short length and small max diameter become restrictive quickly.
5PCS M35 Hex Shank Stubby Set
This set is purpose-built for one scenario: drilling stainless in spaces where a standard drill won’t fit or where an impact driver provides the torque you need. The 1/4″ hex shank locks into any impact driver or quick-change chuck, and the stubby length resists deflection under high thrust.
- Pro: Hex shank compatibility with impact drivers and screw chucks
- Pro: Short body reduces chatter and walking in confined positions
- Con: Only five sizes in a narrow range (3/32″ to 5/16″); not a standalone solution
Skip this if you primarily work on an open drill press or need sizes outside that tight window.
MACXCOIP 29Pcs M35 Cobalt Set
The larger sibling of the 13-piece set, this extends coverage to 1/2″ and includes 29 bits for under sixty dollars. It fills the gap between hobbyist sets and professional inventory, giving a serious DIYer or small fabricator enough sizes for most stainless projects without paying Sinyeenglon prices.
- Pro: Generous 1/16″ to 1/2″ range covers the vast majority of hole sizes
- Pro: Nearly half the price of the 99-piece set for most buyers’ actual needs
- Con: Higher-count sets in this price tier occasionally show less consistent geometry
Skip this if you demand tight tolerances across every size or work in a professional shop that reorders on warranty claims.
Crosstar 21Pcs Three-Flute M35 Cobalt Set
The three-flute design is the differentiator here. More flutes mean more cutting edges per revolution, which translates to faster material removal and reduced heat buildup — the enemy when drilling stainless. For thicker stock where standard two-flute bits bog down, this geometry is a genuine advantage.
- Pro: Three-flute geometry clears chips aggressively, reducing heat and work-hardening
- Pro: Strong performance on stock over 1/4″ thick, where standard bits struggle
- Con: Premium pricing relative to piece count; fewer bits than similar-priced competitors
Skip this if your work is mostly thin sheet metal or small fastener holes where the three-flute advantage is minimal.
GMTOOLS 15Pcs M35 Cobalt Set
At under seventeen dollars, this set pairs M35 cobalt construction with a 135-degree split point and an indexed storage case — features you’d expect to pay double for. The size range of 1/16″ to 3/8″ covers common stainless drilling tasks, and the included case is genuinely useful rather than decorative.
- Pro: Best price-to-feature ratio in this roundup for the included case and geometry
- Pro: 135-degree split point self-starts without center punching as aggressively
- Con: Owner reports on long-term edge retention vary; best suited for intermittent use
Skip this for high-volume production drilling where edge life matters more than upfront savings.
DEWALT DW1361 21 Pc. TiN Coated Set
This set occupies a different niche. The titanium nitride coating excels on wood, plastic, and mild steel but offers marginal benefit on hardened stainless. Still, for a multi-material shop where the drill bit set sees more wood than metal, DEWALT’s pilot-point geometry and brand reliability make it a sensible all-rounder.
- Pro: Pilot point design reduces walking across all materials, not just metal
- Pro: DEWALT warranty and parts availability if a bit breaks prematurely
- Con: TiN coating does not improve stainless performance over bare M35 cobalt
Skip this if stainless is your primary material — a dedicated cobalt set will cut cleaner and last longer on that alloy.
Buying Guide
Cobalt Grade and Substrate
Stainless steel resists cutting because of its chromium content and work-hardening behavior. Cobalt-alloyed high-speed steel (M35 containing roughly 5% cobalt) maintains hardness at the elevated temperatures that develop during stainless drilling. Standard HSS without cobalt softens quickly and produces glazed, oversized holes. TiN coatings add surface hardness but do not improve the substrate’s heat resistance, so for stainless specifically, bare M35 outperforms coated plain HSS. If you see “cobalt” in a product name, verify it says M35 — some sets use the term loosely.
Point Geometry: Split Point and Flute Count
A 135-degree split point bites into stainless without skating across the surface, which is critical because any hesitation creates a work-hardened glaze you cannot drill through afterward. Two-flute bits are standard; three-flute designs clear chips faster and generate less friction heat in thicker sections. Pilot points (as on the DEWALT set) are effective for self-starting on softer materials but less aggressive in stainless than a true split point.
Length, Shank, and Storage
Jobber-length bits suit most bench and drill press work. Stubby-length bits with hex shanks serve impact drivers and confined-space applications where a standard drill cannot reach. For sets over 20 pieces, an indexed storage case is not optional — loose bits in a foam tray damage cutting edges and make finding the right diameter a time sink. If you regularly drop bits or work in the field, prioritize rigid plastic indexing over soft cloth rolls.
Our Verdict
The Sinyeenglon 99Pcs M35 Cobalt Set is the top pick for anyone who drills stainless as a routine part of their work. The full size range, consistent cobalt construction, and organized storage eliminate the most common frustrations: running out of a needed diameter, finding out the cheap bits weren’t real M35, and digging through a drawer to find a 5/32″.
The MACXCOIP 13Pcs wins on budget. For hobbyists whose stainless work involves thin brackets, fittings, and light-gauge sheet in sizes 1/16″ to 1/4″, nothing else delivers true M35 cobalt for under ten dollars.
One condition shifts the recommendation: if you primarily drill stainless stock thicker than a quarter-inch, the Crosstar Three-Flute Set is the better buy regardless of price or piece count, because the geometry advantage in chip clearance and heat management is measurable in practice.
FAQ
Can I drill stainless steel with a regular HSS drill bit?
You can, but the bit will dull almost immediately and the hole will likely be oversized or glazed due to work-hardening. Cobalt-alloyed HSS (M35) maintains its cutting edge at the temperatures stainless generates and produces a cleaner, more round hole.
What speed and pressure should I use on stainless?
Stainless requires slower RPM than mild steel and steady, firm pressure to prevent the bit from skating. Use a cutting fluid or even a light oil to dissipate heat, and never let the bit stop rotating while under pressure — that is when work-hardening occurs.
Do titanium nitride coated bits work on stainless steel?
TiN coating reduces friction on softer materials but does not prevent the substrate from softening under stainless drilling temperatures. A coated plain-HSS bit will still fail on stainless; a bare M35 cobalt bit will outlast it. Coating is a bonus only when combined with an adequate substrate grade.
How do I know if a bit is actually M35 cobalt?
Genuine M35 bits often carry a marking on the shank, and reputable sets list the grade in specifications. Extremely low prices paired with “cobalt” claims are a red flag, since the cobalt content itself carries a material cost that unaffordable pricing cannot support. Owner reviews that mention performance on stainless are the most reliable real-world confirmation.
