Drilling through stainless steel is a test of patience and equipment. Standard high-speed steel bits overheat, dull quickly, and skate across the surface, leaving you with a ruined workpiece and a growing sense of frustration. The key to clean, precise holes in this tough alloy lies in the bit’s material composition, tip geometry, and your drilling technique.
I’m Mohammad Maruf — the founder and writer behind WellFizz. I spend my days dissecting product specifications and analyzing real customer feedback to find tools that actually deliver on their promises for demanding materials.
This guide breaks down the specific features that matter when cutting into hardened metal, so you can confidently pick the right drill for stainless steel without wasting money on bits that fail on the first hole.
How To Choose The Best Drill For Stainless Steel
Stainless steel work-hardens as you drill, which means a dull bit or excessive speed creates a hardened surface that is even harder to penetrate. Choosing the right drill bit is about matching the material composition, tip design, and size range to the specific drilling conditions you face.
Material Composition: Cobalt Content is King
Standard high-speed steel (HSS) bits lack the hot hardness to withstand the friction generated when cutting stainless. Bits made from M35 cobalt steel contain 5% cobalt, which allows them to retain their cutting edge at much higher temperatures. For frequent or heavy-duty stainless work, cobalt bits are a necessity, not a luxury.
Point Geometry: The 135-Degree Split Point
Unlike the standard 118-degree point found on general-purpose bits, a 135-degree split point has a self-centering web that reduces walking on smooth, hard surfaces. This geometry also requires less thrust to initiate the cut, which means cleaner starts and less operator fatigue — a critical factor when drilling through stainless sheet or plate.
Finish and Flute Design
Surface finishes like black oxide, gold oxide, and titanium nitride reduce friction and protect the bit from heat damage. A parabolic flute design, often seen on impact-rated bits, actively pulls chips out of the hole to prevent clogging and overheating. For deep holes in stainless, flute geometry is just as important as the cutting edge itself.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Milwaukee 48-89-4680 | Titanium | Impact drivers and fast cuts | Parabolic flute + 1/4″ hex shank | Amazon |
| HIDOTOL 29-Piece Cobalt | Cobalt | Hardened metal drilling | M35 cobalt steel (5% Co) | Amazon |
| Sinyeenglon 99-Piece Cobalt | Cobalt | High-volume production | 99 bits, full grinding process | Amazon |
| CaRoller 29-Piece HSS | HSS | Mild steel and light stainless | W4 HSS with black/gold oxide | Amazon |
| KSEIBI Step Drill Set | Step | Thin metal and sheet work | 3-piece, dual-flute design | Amazon |
| BeHappy 29-Piece HSS | HSS | Budget-friendly general use | HSS with black/gold oxide | Amazon |
| MACXCOIP Metric 25-Piece | Cobalt | Metric machining and repairs | M35 cobalt, 1.0mm-13.0mm | Amazon |
In‑Depth Reviews
1. Milwaukee 48-89-4680 18-Piece Shockwave Impact Duty Thunderbolt Titanium Drill Bit Set
Milwaukee’s Shockwave line is engineered for impact drivers, and the 48-89-4680 set brings that same rugged DNA to stainless steel. The titanium coating reduces heat buildup significantly, allowing these bits to cut through stainless sheet and brackets without the tip softening during rapid-fire drilling. Users consistently report minimal warping and clean holes even when working through multiple pieces in a single session.
The parabolic flute form is a standout feature — it actively pulls chips up and out of the hole rather than letting them pack and generate friction. On a material like stainless that loves to work-harden, good chip evacuation is the difference between a smooth cut and a jammed bit. The 135-degree split point also helps the bit bite immediately without skating across the surface.
The set includes 18 bits with common sizes like 1/16″, 1/8″, 3/16″, and 1/4″, with two duplicates of the most frequently used diameters. The hex shank locks into impact chucks without slipping, a major advantage if you run a cordless impact driver instead of a traditional drill. The hard plastic case with individual slots keeps everything organized on the job site.
Why it’s great
- Parabolic flute design clears chips rapidly, reducing heat in stainless
- Hex shank fits securely in impact drivers without chuck slippage
- Durable titanium coating resists heat and extends bit life
Good to know
- Limited to 18 pieces — fewer size increments than 29-piece sets
- Primarily designed for impact drivers, not drill presses
2. HIDOTOL Cobalt Drill Bit Set 29 PCS M35 High Speed Steel
For those regularly drilling into hardened alloys, the HIDOTOL 29-piece set is a dedicated stainless solution. Constructed from M35 high-speed steel with 5% cobalt content, these bits maintain their hardness at elevated temperatures where standard HSS bits would soften and fail. The gold oxide finish adds a layer of corrosion resistance and reduces friction as the bit penetrates the metal.
Users drilling through stainless steel plate report that the 135-degree split point centers reliably without a center punch, and the fully ground twist design clears particles faster than rolled bits. One user drilling into 1/8″ stainless on a drill press at 300 RPM generated consistent 8-inch spiral chips without overheating — a strong indicator of proper geometry and material integrity.
The jobber-length bits range from 1/16″ to 1/2″ in 1/64″ increments, covering most fabrication and repair tasks. The indexed round case keeps each bit in its own slot, making size selection quick. For anyone who needs a dedicated stainless steel drilling set without stepping up to a full industrial solution, this is a solid mid-range investment.
Why it’s great
- M35 cobalt steel retains edge hardness under high drilling temperatures
- Self-centering split point reduces walking on smooth stainless surfaces
- Complete 29-size range from 1/16″ to 1/2″ in 1/64″ steps
Good to know
- Requires slow speeds and cutting oil for best stainless performance
- Small sizes can snap if excessive side pressure is applied
3. Sinyeenglon Cobalt Drill Bits Set 99Pcs M35 High Speed Steel
If you burn through small bits regularly or work in a shop where multiple diameters are needed simultaneously, the 99-piece Sinyeenglon set offers a massive inventory of M35 cobalt bits. The set includes duplicates of smaller sizes — 16 pieces of 1/16″, 16 of 5/64″, 15 of 3/32″ — which directly addresses the common problem of snapping tiny bits in hardened steel and having to pause a job to order replacements.
The hardened full grinding process delivers consistent edge geometry, and the 135-degree split point is present on every bit. Users drilling through thick steel beams and 1″ blocks note that these bits outperform standard titanium-coated options when run at the correct slow speed with lubrication. The reduced shank on larger sizes allows them to fit standard drill chucks without needing a separate adapter.
The hard plastic storage case is compartmentalized with size labels printed on the underside of the lid. While the included stickers are low quality, the case itself is sturdy enough for daily shop use. For anyone who drills stainless as a routine task rather than an occasional project, this set delivers the volume and material quality needed to keep working without frequent bit changes.
Why it’s great
- 99 pieces with multiple duplicates of common small sizes reduce downtime
- M35 cobalt holds up to thick steel and hardened alloys without softening
- Full grinding process ensures consistent cutting edge on every bit
Good to know
- Case stickers for size labeling are poor — engraved labels would be better
- Does not include bits larger than 3/8″
4. CaRoller 29Pcs Drill Bit Set, 135 Degree Tip High Speed Steel
The CaRoller set hits a sweet spot for DIYers who occasionally tackle stainless but mainly work with mild steel, aluminum, and plastics. Made from W4 high-speed steel with a black and gold oxide finish, these bits offer better wear resistance than untreated HSS without jumping to cobalt pricing. One user drilled 30 holes in a steel I-beam with a single bit before noting significant wear, demonstrating reasonable durability for the cost.
The 135-degree split point and fully ground twist design help reduce friction and prevent walking on hard surfaces. Users report that with proper technique — slower speeds, cutting oil, and steady pressure — these bits handle 1/8″ stainless plate effectively. One reviewer on a drill press at 300 RPM generated clean spiral chips, a sign that the edge geometry is consistent across the set.
The 29-piece range covers 1/16″ to 1/2″ in 1/64″ increments, and the impact-resistant plastic case keeps everything organized. While these are not cobalt bits and will dull faster on heavy stainless use, they provide a cost-effective entry point for someone who needs a versatile set that can handle occasional hardened metal work without breaking the bank.
Why it’s great
- Dual black and gold oxide finish improves corrosion and wear resistance
- 135-degree split point prevents walking on smooth surfaces
- Good balance of performance and cost for mixed-material drilling
Good to know
- Not cobalt — will dull faster on frequent heavy stainless use
- Some users report bits spinning in the chuck due to smooth shank
5. KSEIBI Unibit 3-Piece High-Speed Steel Step Drill Bit Set
When drilling larger holes in thin stainless sheet — think electrical panels, enclosures, or automotive body work — step bits offer a cleaner, faster solution than swapping between multiple twist bits. The KSEIBI 3-piece set uses high-speed steel M2 material with a black oxide finish and a dual-flute design that claims up to 4X longer life and 50% more holes per battery charge compared to standard step bits.
Users drilling into steel for a shipping container home and various aluminum brackets report smooth, non-grabbing cuts with no overheating. The 135-degree tapered tip and 1/4″ hex shank allow these to be used in standard drills and impact drivers, and the spiral flute design actively evacuates chips to prevent binding. The three included bits cover a wide range of common hole sizes without needing a full set of individual twist bits.
One important caveat: the step design is optimized for thinner materials. One user snapped a bit at the shank when using it in an impact driver on a torch-cut trailer hole — a high-stress scenario that exceeds what step bits are designed for. For clean, deburred holes in stainless sheet up to about 1/8″ thick, this set is an excellent specialized addition to any toolkit.
Why it’s great
- Dual-flute design delivers fast, clean cuts in thin stainless
- Hex shank prevents slipping in impact drivers and drill chucks
- Three bits cover multiple hole sizes without changing bits
Good to know
- Snaps under high side-load — not for heavy structural or torch-cut steel
- Not a replacement for twist bits on thick plate or deep holes
6. BeHappy 29Pcs Cobalt Drill Bit Set, 135 Degree Tip High Speed Steel
The BeHappy 29-piece set is positioned as an entry-level option for those who need a wide range of sizes without a premium price tag. The bits are made from high-speed steel with a black and gold oxide finish designed to improve corrosion resistance and wear. For light to moderate drilling in mild steel, cast iron, and thin stainless, users report that they cut effectively and stay sharp through reasonable use.
The 135-degree split point is present across all sizes, which helps with self-centering and reduces the walking issue common on hard surfaces. Multiple users note that using cutting oil and a slow speed is essential to prevent overheating — standard advice for any HSS bit on stainless. One user mentioned that the bits can spin in the drill chuck if not tightened adequately, likely due to the smooth round shank.
The set covers 1/16″ to 1/2″ in 1/64″ increments and comes in a metal indexed storage case. While some users reported burning up a few bits on harder materials, the overall consensus is that these perform well for the price point. This set is best suited for DIYers who need a complete size range and are willing to accept faster wear on heavy stainless compared to cobalt alternatives.
Why it’s great
- Complete 29-size range from 1/16″ to 1/2″ in a metal case
- Gold and black oxide coating adds corrosion resistance
- Budget-friendly entry point for building out a drill bit collection
Good to know
- HSS material dulls faster on hardened stainless than cobalt bits
- Some bits may slip in chuck due to smooth shank finish
7. MACXCOIP Metric 25Pcs M35 Cobalt Drill Bit Set, 1.0mm-13.0mm
Anyone working on metric machinery, European equipment, or 3D-printed parts that require precise metric hole sizes will appreciate the MACXCOIP 25-piece set. Using M35 cobalt steel with a 135-degree split point, these bits are built for hardened metals including stainless steel, cast iron, and tough alloys. The set covers 1.0mm to 13.0mm in 0.5mm steps, a range that covers most small-to-medium metric fasteners and fittings.
A former CNC machinist reviewed these bits and confirmed the cobalt material quality is genuine — the edge holds up through repetitive use on stainless without glazing. The 135-degree tip geometry prevents walking and reduces the thrust needed for penetration, which is especially helpful with the smaller diameters that are prone to bending under pressure. The straight shank fits standard drill chucks without issue.
The plastic storage case is flat enough to fit in shallow tool chest drawers, and the size indexes make it easy to find the right bit quickly. One user noted that a bit slipped in their drill press chuck, possibly indicating slight shank tolerance variation. For metric-focused shops and hobbyists who need cobalt durability in a precise size range, this set fills a gap that fractional inch sets cannot cover.
Why it’s great
- M35 cobalt steel provides genuine hardness for stainless and hardened alloys
- Metric 0.5mm step increments from 1.0mm to 13.0mm
- Compact case fits shallow tool chest drawers for easy storage
Good to know
- Not for use on quenched bolts — cobalt can still chip on extreme-hardness steel
- Some users report occasional shank slipping in drill press chucks
FAQ
Can I use standard HSS bits on stainless steel?
What speed should I use when drilling stainless steel?
How can I stop the drill bit from walking on stainless steel?
Do I need cutting oil for stainless steel?
Final Thoughts: The Verdict
For most users, the drill for stainless steel winner is the HIDOTOL 29-Piece Cobalt Set because it combines genuine M35 cobalt material with a full 29-size range and consistent 135-degree split points, offering the best balance of durability and coverage for regular stainless work. If you need impact driver compatibility and high-speed chip evacuation, grab the Milwaukee Shockwave 18-Piece Set. And for high-volume shops that burn through small bits, nothing beats the value of the Sinyeenglon 99-Piece Cobalt Set with its extensive duplicate inventory of frequently used sizes.
Mo Maruf
I created WellFizz to bridge the gap between vague wellness advice and actionable solutions. My mission is simple: to decode the research and give you practical tools you can actually use.
Beyond the data, I am a passionate traveler. I believe that stepping away from the screen to explore new environments is essential for mental clarity and physical vitality.