Drilling into sheet metal often turns into a battle with wandering tips, torn edges, and bits that dull after a single use. The right tool for the job determines whether you get a clean, burr-free hole or a frustrating mess that ruins your workpiece.
I’m Mo Maruf — the founder and writer behind The Tools Trunk. I analyze manufacturing tolerances, cutting geometry, and material hardness data from dozens of brands to find which drills actually hold an edge against galvanized steel and stainless sheet.
This guide breaks down the five most capable sets available right now, matching each to specific metal thicknesses and hole sizes. Whether you need a portable kit for job-site panels or a heavy-duty step bit for enclosure work, the drill bit for sheet metal you choose must match the material stack-up and spindle speed you run.
How To Choose The Best Drill Bit For Sheet Metal
Sheet metal drilling demands aggressive point geometry and a material hard enough to resist heat softening. Standard wood bits skate across the surface and burnish rather than cut. Focus on three factors: steel alloy, point angle, and flute design.
Steel Alloy and Hardness
HSS bits work for thin aluminum and mild steel up to 16 gauge. For stainless, hardened steel, or repeated production holes, M2 HSS or 5% cobalt steel retains hardness above 67 Rockwell C, resisting edge breakdown at higher spindle speeds.
Point Geometry and Self-Centering
A 135-degree split point is essential for sheet metal. It creates a chisel edge that bites into the surface immediately, eliminating the need for a center punch in most cases. Standard 118-degree points wander badly on convex surfaces and thin wall stock.
Step Bits Versus Twist Bits
Step bits with double-flute cutting edges produce clean, burr-free holes in thin sheet without the chatter of twist drills. They let you drill multiple sizes with one bit, ideal for electrical enclosures and chassis work. Twist bits excel when drilling deeper holes in thicker plate.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Jerax tools Step Bit | Step Bit | Stainless sheet up to 12 ga | M2 HSS, nitride surface | Amazon |
| Anfrere 12-Piece Step Set | Step Set | Multi-size hole drilling in thin metal | HSS with Ti coating, 2‑3/8″ max | Amazon |
| WildBossy M35 Cobalt Set | Twist Set | Hardened steel and stainless plate | 5% cobalt, 135° split point | Amazon |
| PLATINUMEDGE Step Set | Step Set | General sheet metal and DIY | 4241 HSS, nitride coated | Amazon |
| CaRoller 29-Piece Set | Twist Set | Job-site versatility, mixed materials | W4 HSS, black and gold finish | Amazon |
In‑Depth Reviews
1. Jerax Tools 1/4 to 1-3/8 Inch Step Drill Bit
This single step bit uses M2 high-speed steel — the same alloy found in premium end mills — with a vacuum heat treatment and nitride surface layer that pushes wear resistance far beyond bargain-bin HSS. The 12-gauge stainless steel limit is genuine; multiple users report clean holes in stainless sinks and fire pit iron without edge glazing.
The five marked sizes (7/8″ through 1-3/8″) are laser-engraved in the flute, so you never stop mid-drill to guess the diameter. Double-flute geometry evacuates chips quickly, preventing the packing that causes step bits to bind in thicker material. At 1.38″ maximum cut, this bit handles standard knockout work and grommet openings in one pass.
Professional electricians and sheet metal workers consistently praise the burr-free finish on 25-gauge panels. The trade-off is that this is a single bit, not a set — if you need multiple hole diameters across different jobs, you must pair it with another tool. Still, for the most common enclosure sizes, nothing in this roundup cuts cleaner.
What works
- M2 alloy with nitride treatment outlasts standard HSS 3-to-1 in stainless
- CNC-ground flute edges produce burr-free holes on thin sheet
- Engraved size markings eliminate guesswork during drilling
What doesn’t
- Single bit covers only five hole sizes; no compact storage case
- Requires appropriate feed pressure on stainless to avoid heat buildup
2. Anfrere 12 Sizes Step Drill Bit Set
When your panel work demands hole sizes from 1/4″ all the way up to 2-3/8″, this 12-piece set eliminates the need to swap between multiple step bits. Each bit carries a titanium-coated HSS body with polished flute surfaces that reduce friction and keep cutting edges cooler during extended runs on aluminum and copper sheet.
The laser-engraved size markings sit inside the flute, visible even after months of shop use. Double-flute chip evacuation works well on materials up to about 14-gauge mild steel, though the manufacturer explicitly warns against heavy use on hardened steel — this set targets softer sheet metal and general handyman work rather than production stainless drilling.
Users report smooth cuts through steel electrical boxes and copper cladding without the grabbing often seen on uncoated step bits. The 1.4-pound kit comes in a sturdy case that keeps bits organized. For home DIY and light commercial jobs where you need every common knockout size, this set offers the broadest range in the list.
What works
- Twelve bits cover 1/4″ through 2-3/8″ for maximum versatility
- Titanium coating reduces cutting friction and heat on non-ferrous metals
- Durable case with clear lid keeps the set organized and visible
What doesn’t
- HSS substrate limits performance on hardened steel and thick stainless
- Some users note durability concerns after repeated use on steel
3. WildBossy M35 Cobalt Drill Bit Set
If your sheet metal work involves hardened steel, stainless plate, or even broken tap extraction, the 5% cobalt content in this 20-piece twist set delivers the hardness needed to cut where standard HSS fails. M35 cobalt steel measures up to 67 Rockwell C, and the 135-degree split point immediately bites into the work surface without walking.
Sizes run from 1/16″ up to 1/2″ in a jobber-length index case — ideal for structural steel brackets, thin stainless panels, and cast iron. The 3-flat shank design prevents the bit from spinning inside the drill chuck under heavy load, a common issue with completely round shanks on smooth-surface drilling.
Users drilling through stainless steel report clean spiral chips at 300 RPM with cutting oil, and the bits held their edge through multiple passes on 1/8″ material. A small number of units arrived with a dull bit or snapped on first use, but the majority of feedback confirms these bits cut with authority when run at appropriate speeds with lubrication.
What works
- 5% cobalt alloy cuts hardened stainless and cast iron far longer than HSS
- 135-degree split point self-centers without a pilot punch on most surfaces
- 3-flat shank eliminates chuck slippage under heavy torque
What doesn’t
- Not suitable for glass or ceramic materials; brittle cobalt can chip
- Occasional quality inconsistency reported with individual bits in the set
4. PLATINUMEDGE Step Drill Bits Set
This five-piece step set packs 50 individual hole sizes across the five bits, covering everything from 3/16″ up to 1-3/8″. The 4241 HSS alloy with nitride black coating and polished flute surfaces provides a solid middle ground between economy-grade steel and premium cobalt — it drills aluminum, copper, and mild steel sheet with consistent edge retention.
The double-flute design on each bit clears chips effectively in thin material, and the nitride finish reduces friction to keep the bit running cooler during longer cutting sequences. Multiple users report using these bits five days a week on job-site panels with no noticeable dulling, which is a strong indicator of consistent heat treatment quality.
The clear-lid plastic storage box keeps the set organized, and the five-bit lineup means you rarely need to reach for a separate twist drill. The main limitation is material hardness — 4241 HSS struggles with thick stainless and hardened alloys, so keep these to mild steel, galvanized sheet, and non-ferrous metals for best results.
What works
- Five bits with 50 step sizes cover nearly every common hole diameter
- Nitride black coating and polished edges improve chip flow and reduce heat
- Users confirm daily use on steel panels without early edge failure
What doesn’t
- 4241 HSS alloy lacks the hardness for thick stainless or hardened steel
- Plastic case hinges may break under heavy shop use over time
5. CaRoller 29-Piece Drill Bit Set
This 29-tool set provides the broadest size range of any entry on this list — every fractional inch from 1/16″ up to 1/2″ — making it a true one-stop solution for electricians and metal fabricators who work across multiple gauge thicknesses. The W4 high-speed steel body combined with a black oxide and amber coating delivers above-average wear resistance for a general-purpose kit.
The 135-degree split point is consistent across the entire set, so every bit self-centers without a pilot punch on smooth sheet metal surfaces. Users report cutting cleanly through 1/8″ stainless plate on a drill press at low RPM with cutting oil, producing long spiral chips that indicate proper geometry and sharp edges.
The indexed storage case keeps every bit in its correct slot, though some users note the case slots fit tightly — reinserting a used bit can mark the coating. This set excels when you need a complete range of sizes for job-site work where material varies wildly, from electrical panels to steel bar stock, but individual bit durability is closer to mid-range than pro-grade.
What works
- 29 bits cover 1/16″ to 1/2″ with no gaps for maximum job-site versatility
- 135-degree split point on every bit eliminates pilot hole requirement
- Black oxide and amber coating reduces friction during extended drilling
What doesn’t
- Case slots are tight; inserting used bits risks scuffing the coating
- W4 HSS substrate is not cobalt-grade; thick stainless cuts require care
Hardware & Specs Guide
M2 High-Speed Steel vs. Standard HSS
M2 contains roughly 50% more tungsten and 150% more molybdenum than standard HSS. These elements form hard carbide particles in the steel matrix, allowing the bit to maintain its cutting edge at temperatures that would anneal a standard HSS bit. For sheet metal work involving stainless steel or repetitive production runs, M2 is the minimum alloy grade worth considering.
Step Bit Flute Geometry
Double-flute step bits cut faster and evacuate chips more efficiently than single-flute versions. The spiral or straight groove pattern matters less than the polished finish on the flute surfaces — polished flutes reduce friction and prevent chip welding in aluminum and galvanized sheet. Look for CNC-ground flutes on any step bit used for finish-critical work.
135-Degree Split Point Mechanics
The split point removes the chisel edge at the center of the bit tip, creating two cutting edges that meet at a sharp point. This geometry reduces the axial force needed to start the cut by about 50% compared to a standard 118-degree point, which is especially critical on thin sheet metal where downward pressure can bend the workpiece.
Cobalt Percentage and Real-World Impact
M35 cobalt steel contains 5% cobalt, while M42 contains 8%. The cobalt acts as a binder for carbide particles, improving red hardness — the bit’s ability to stay hard at high cutting temperatures. For occasional stainless drilling, 5% cobalt is sufficient. For production drilling in hardened steel or titanium, the 8% variant is preferable but costs significantly more.
FAQ
Do I need a center punch when using a 135-degree split point drill bit on sheet metal?
Can I use a standard wood drill bit on thin steel sheet metal?
What RPM should I run when drilling stainless steel sheet metal with a 5% cobalt bit?
Why does my step bit leave a burr on the back side of the hole?
Final Thoughts: The Verdict
For most users, the drill bit for sheet metal winner is the Jerax Tools 1/4 to 1-3/8 Inch Step Bit because its M2 HSS with nitride hardening delivers burr-free holes in stainless and mild steel with minimal walking. If you need the broadest size range for mixed-material job-site work, grab the CaRoller 29-Piece Set. And for drilling hardened steel plate or thick stainless where edge retention is critical, nothing beats the WildBossy M35 Cobalt Twist Set.