7 Best Bit For Drilling Aluminum | Six Flutes, One Choice

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Drilling aluminum is a game of friction and feed rate. Squeeze too hard and the bit grabs, chatter runs up your arm, and you end up with a torn, oversized hole instead of a clean circle. The right bit for your workbench or truck-bed project avoids all that frustration — it starts cutting immediately, stays sharp through multiple holes, and leaves edges smooth enough that you do not need a deburring tool (a tool that cleans rough metal edges) afterward.

I’m Min — the founder and writer behind Gadgets Feed. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.

Bit For Drilling Aluminum — we break down seven of the best options, from a budget step bit that punches through like butter to a premium cobalt set built for hardened metal and repeat use.

Quick Picks

How To Choose The Best Bit For Drilling Aluminum

Aluminum is soft enough to grab a standard bit and hard enough to weld it into the flutes (the helical grooves) if you push too fast. The ideal bit clears chips, stays cool, and enters the work without walking across your layout line. Here are the three things savvy buyers check first.

Material: HSS vs. M2 vs. Cobalt

Standard high-speed steel (HSS) works fine for occasional holes in thin sheet aluminum. If you are drilling thicker plate, cast aluminum, or production runs, step up to M2 HSS or M35 cobalt steel. The extra hardness resists heat buildup so the edge stays sharp longer.

Flute Geometry: Spiral vs. Straight

Spiral flutes (twisted grooves) pull chips up and out of deep holes, making them ideal for block aluminum or angle iron. Straight flutes on a step bit are better for thin sheet because they shave the material rather than trying to eject a long chip that can clog and gall (stick to the bit).

Point Style: Split Point vs. Standard

A split-point tip (a small notch ground into the center of the cutting edge) lets the bit start on the mark without wandering. This is especially important on aluminum because the metal is soft enough that a standard point can skate across the surface and spoil your layout.

Quick Comparison

Model Best For Material Flutes Range Amazon
M2 HSS Quick Change 1/4″-3/4″ Heavy-duty stainless & steel M2 HSS 2 1/4″ – 3/4″ $17.95Amazon
Jerax 3/16″-7/8″ M2 Step Large-hole versatility M2 HSS 2 3/16″ – 7/8″ $17.49Amazon
AIMLENTOOL 1/4″-1-3/8″ M2 Extra-large diameters M2 HSS 2 1/4″ – 1-3/8″ $18.98Amazon
GMTOOLS M35 Four-Flute Cobalt Clean, fast cuts in metal M35 Cobalt 4 1/8″ – 1/2″ $16.99Amazon
Jerax HSS 1/8″-1/2″ Step Budget-friendly sheet metal HSS 2 1/8″ – 1/2″ $14.95Amazon
BECOLLO 1/2″ Titanium Twist Repeatable pilot holes HSS + Ti 2 1/2″ (set of 3) $15.99Amazon
WildBossy M35 Cobalt 20-Piece Full jobber-size kit M35 Cobalt 2 1/16″ – 1/2″ $27.99Amazon
↻ Live Amazon prices — as of Jul 5, 2026 3:12 AM. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product. As an Amazon Associate I earn from qualifying purchases. CERTAIN CONTENT THAT APPEARS ON THIS SITE COMES FROM AMAZON. THIS CONTENT IS PROVIDED "AS IS" AND IS SUBJECT TO CHANGE OR REMOVAL AT ANY TIME. Amazon and the Amazon logo are trademarks of Amazon.com, Inc. or its affiliates.

In‑Depth Reviews

Heavy-Duty Champion

1. M2 HSS Quick Change 1/4″ – 3/4″ Step Drill Bit

Quick-Change Hex ShankNitride Surface Hardening

A beast for heavy steel that stays sharp hole after hole.

This M2 HSS step bit is built for the kind of drilling that kills a basic bit — It survived eight holes in high-strength steel (six at 7/8″ and two at 3/4″) and stayed sharp after the last hole, according to one buyer. Its minimum bore diameter of 0.25 inches starts larger than the Jerax HS step bit below (0.13 inches), but that trade-off buys you a tougher edge on thick steel and stainless. You get nine marked sizes from 1/4″ to 3/4″, and the quick-change 1/4-inch hex shank (a six-sided shaft that lets you swap bits without re-chucking your drill) works with impact drivers and standard chucks. The polished steps let you see your target size mid-drill so you never have to stop and measure. Another buyer commented that it cut through 3mm stainless steel cleanly and easily many times over, remaining sharp after the tenth hole.

What holds up

  • Drills clean holes in thick steel and stainless — buyers confirm sharpness after a dozen holes.
  • Quick-change hex shank works with impact drivers and standard chucks.
  • Polished step markings let you read hole size while the bit is spinning.

Know before you buy

  • Starts at 1/4″ — too wide for very small pilot holes (starter holes).
  • Two-flute design is stable but removes chips slower than a four-flute bit.

This is the pick for anyone who regularly drills into 3mm+ stainless or hardened steel and needs a single bit that survives a full work session. The main limitation: it does not cover hole sizes below 1/4″ — you will still need a separate starter bit for tiny diameters.

Widest Range

2. Jerax 3/16″ – 7/8″ M2 Step Drill Bit

12 Marked Sizes118° Split Point

One bit, twelve holes, clean cuts on everything from aluminum to stainless.

With a cutting diameter of 0.88 inches (7/8″), this step bit goes larger than the GMTOOLS M35 cobalt bit at 0.5 inches (1/2″). That means you can drill a 7/8″ hole in a single pass without swapping tools. The M2 HSS construction, per the maker, helps the edge resist heat when you lean on it in galvanized steel or thicker aluminum plate. Its minimum bore diameter is 2.8 millimeters (3/16″), versus the BECOLLO twist bit’s 12.7 millimeters (1/2″), which lets you start small and step up gradually. The 118° split-point tip (the notch ground into the cutting edge) centers itself on thin sheet without walking. All twelve sizes from 3/16″ to 7/8″ are laser-marked and polished so you read the size mid-drill without stopping.

Why it stands out

  • Wide size range — twelve different holes from one bit.
  • M2 HSS with nitride hardening adds durability over basic HSS step bits.
  • Starts very small at 2.8mm for precise entry holes.

Check this first

  • 118° point angle (the shape of the tip) is less aggressive for self-centering than a 135° split point.
  • No customer reviews available yet to confirm long-term edge life.

Ideal when you need one tool that handles everything from small 3/16″ holes to large 7/8″ knockouts in a single session. The potential catch: the steeper 118° tip may require a center punch (a tool that makes a small dent to guide the bit) on very smooth aluminum to keep from walking.

Extra-Large Reach

3. AIMLENTOOL 1/4″ – 1-3/8″ M2 Step Drill Bit

19-Step SizesUncoated M2 HSS

Nineteen steps up to 1-3/8″ — the widest single-bit range in this lineup.

If you need a hole larger than 7/8″, this is the only step bit here that gets you there. With a cutting diameter of 1.38 inches (1-3/8″) and nineteen incremental steps starting at 3/16″, it covers sizes that normally require a knockout punch (a tool that punches a clean hole) or a hole saw. The M2 HSS construction is noticeably stronger than basic HSS, and the split-point tip allows self-starting without a pilot hole. The straight-groove two-flute design keeps chips moving in softer metals like aluminum and copper, so the bit runs cooler during long drilling stretches. There are no customer reviews in the data yet, so long-term edge-life is unconfirmed, but the 30-day money-back guarantee from the maker gives some confidence for risk-free shopping.

What you gain

  • Huge top-end diameter — drills up to 1-3/8″ without switching tools.
  • Nineteen step sizes mean fine adjustment for odd-sized holes.
  • Split point walks less on start-up.

What is missing

  • Uncoated steel — no TiN or nitride layer for extra heat resistance.
  • No buyer reviews yet to verify durability on thick material.

Reach for this if your work frequently involves 1″ to 1-3/8″ holes that a standard step bit cannot cover. Look elsewhere if you plan to drill hardened stainless often — the uncoated M2 may dull faster than a nitride or TiAlN-coated bit.

Four-Flute Performer

4. GMTOOLS M35 Four-Flute Cobalt Step Drill Bit, 1/8″ – 1/2″

Four FlutesTiAlN Coating

Four cutting edges mean a smoother finish at higher feed rates.

Most step bits on this list use two flutes. The GMTOOLS M35 cobalt bit has four flutes, while the HSS step bits from Jerax have two, which translates to faster material removal and a cleaner surface finish on aluminum sheet. It also has a TiAlN (titanium aluminum nitride) coating that stands up to high oxidation temperatures (about 1,500°F), and buyers report it drilled 200+ hooks (which are small metal pieces) without dulling. The M35 cobalt steel base handles red heat (the temperature at which steel glows red) better than standard HSS, so you can push harder on stainless without cooking the edge. Its 1/4-inch hex shank (a six-sided grip) locks into impact drivers and drill chucks alike. The range runs from 1/8″ to 1/2″, while the Jerax 3/16″-7/8″ step bit runs from 3/16″ to 7/8″, so it is best suited for smaller holes in gauge metal (thin sheet metal) and thin plate.

Four-flute advantage

  • Four flutes cut faster and leave a smoother edge than two-flute designs.
  • M35 cobalt steel with TiAlN coating resists heat and wear — owners mention 200+ holes without dulling.
  • Hex shank works with impact drivers for quick bit swaps.

Keep in mind

  • Top size is only 1/2″ — not for large-diameter holes.
  • One reviewer noted completely dull bits that failed on mild steel sheet metal.

Best for detailed fabrication work where finish matters and you need a bit that survives hundreds of small holes in metal. The honest downside: quality may vary — a few units in the run arrived dull, so inspect the tip before your first use.

Budget Step Star

5. Jerax HS 1/8″ – 1/2″ Step Drill Bit

13 Marked SizesNitride Finish

Durable, sharp, and cheap enough to replace without guilt.

This unibit (a step bit that lets you drill many hole sizes) from Jerax is the most affordable step bit here, and buyers confirm it works. One reviewer wrote that it is “durable af, drill through aluminum like butter, sharp and effective, great price.” The HSS material with a nitride finish gives it decent edge life on soft metals, and the split-point tip (a notch that helps the bit start without wandering) starts without a pilot hole (a small starter hole) in aluminum, copper, or plastic. Its minimum bore diameter is 0.13 inches (1/8″), versus the M2 Quick Change bit’s 0.25 inch (1/4″) start, so you can drill 1/8″ pilot holes that the premium bit cannot reach. Thirteen marked sizes from 1/8″ to 1/2″ cover common electrical-box knockouts and sheet-metal pass-throughs. The trade-off is that basic HSS dulls faster than M2 or cobalt on steel — keep this one for aluminum and occasional mild steel only.

Punching above its cost

  • Very affordable price for a 13-size step bit.
  • Customers note it drills aluminum like butter — sharp out of the pack.
  • Starts as small as 1/8″ for fine pilot holes.

Where it falls short

  • Standard HSS will not hold up to heavy steel or stainless work.
  • A few users noted slightly ragged edges that needed light sanding.

Smart pick for weekend DIYers who drill aluminum, copper, and plastic and want a capable step bit at a low entry cost. The workload of daily stainless or hardened metal demands M2 or cobalt instead.

Pilot Hole Trio

6. BECOLLO 1/2″ Titanium Twist Drill Bits Set (3-Pack)

1/2″ Diameter135° Split Point

Three identical 1/2″ bits for repetitive pre-drilling without reaching for a step bit.

When you are pre-drilling decking screws in heavy 2×10 pressure-treated lumber, one bit can overheat and dull before you finish the job. Reviewers point out that this BECOLLO trio outlasts multiple 5/32″ (approx. 0.16 inch) bits on the same project — the titanium coating resists rust and cuts friction so the HSS steel underneath stays sharp longer. The 135° split point (the notch that helps it self-center) self-centers on aluminum sheet without walking, which saves you from patching skate marks later. Each bit cuts to a 12.7 millimeter diameter (1/2″) with a straight shank. Three bits in a plastic case means you have two backups when you drop one into a floor cavity or dull the first on a hidden weld. The bevel-style point (a slight angled edge) is aggressive enough for metal but the bits are twist-flute (spiral grooves), so they are better suited for through-holes (holes that go all the way through) in stack-drilling than for step drilling thin sheet.

Why three of the same

  • Multiple identical bits eliminate downtime — grab a fresh one when the first dulls.
  • Titanium coating prevents rust and reduces friction on aluminum.
  • Buyers confirm it outlasts smaller bits on pressure-treated lumber.

Noted limits

  • Each bit is 1/2″ only — no graduated sizes here.
  • Twist flute design can clog with aluminum chips in deeper holes.

Grab this set when you need repeatable 1/2″ pilot holes across a large job site and want spares ready in a case. If you need a single bit that covers multiple diameters, a step bit is more versatile.

Full Kit Cobalt

7. WildBossy M35 Cobalt Drill Bit Set (20-Piece)

20 Sizes135° Split Point

Twenty jobber-length (standard length for general use) cobalt bits with a maker-claimed longer life than HSS.

This is the only true twist-bit set in the lineup — 20 sizes from 1/16″ to 1/2″ (including duplicates of the most common sizes like 3/32″, 1/8″, and 3/16″ each with two bits). The M35 cobalt steel measures up to 67 Rockwell hardness (a scale that measures how hard a material is), so it powers through hardened metal and aluminum alloys without chipping. The 135° split point (the notch for self-centering) centers aggressively on the mark. Each bit has a precision-ground three-flat shank (three flat sides on the shaft) that grips the chuck (the part of the drill that holds the bit) without slipping under load. The titanium surface coating adds a layer of wear resistance. At 15.2 ounces for the whole kit, the plastic case is easy to toss into a toolbox. There are no customer reviews in the data yet for this specific listing, so the maker’s longevity claim should be tested against real use.

Kit strengths

  • Twenty bits cover almost every hole size from 1/16″ to 1/2″.
  • M35 cobalt steel handles hardened metal where HSS dulls quickly.
  • Three-flat shank prevents chuck slip during heavy drilling.

What to verify

  • No verified buyer reviews yet to confirm bit life.
  • The kit does not include sizes above 1/2″ — large holes still need a step bit.

Take this kit if you want a single purchase that covers a full range of twist-drill sizes and need cobalt hardness for mixed-metal drilling. If you mostly drill thin sheet aluminum, a single step bit is cheaper and faster for that work.

Understanding the Specs

M2 vs. M35 Cobalt Steel

M2 high-speed steel stays sharper on harder materials like stainless and galvanized steel. M35 cobalt steel adds 5% cobalt, pushing hardness to around 67 Rockwell — ideal for production drilling or abrasive aluminum alloys that wear out standard edges quickly.

Flute Count: 2 vs. 4

A two-flute step bit evacuates chips well and is easier to resharpen. A four-flute bit like the GMTOOLS M35 leaves a smoother surface because there are more cutting edges engaging the work. The trade-off is that four-flute bits can clog more easily in very soft aluminum (galling) and are harder to sharpen by hand.

Step Bit vs. Twist Bit

Step bits cut a cone-shaped hole that widens as you push through — perfect for thin sheet and enclosures where you need multiple hole sizes from one tool. Twist bits cut a fixed diameter straight through the material — better for deep holes in thick plate or for pre-drilling before tapping (cutting threads for a screw). Aluminum chips evacuate better through spiral twist flutes than straight step grooves in deep holes.

Minimum Bore Diameter

This is the smallest hole the bit can make on its first step. A lower value (like 0.13 inches on the Jerax HS step bit) lets you start small and step up gradually, reducing the chance of the bit grabbing and walking. A higher value (like 12.7 millimeters on the BECOLLO twist bit) means you must already have a pilot hole or you will have to force the wider tip into the material.

FAQ

What is the best material for a drill bit that drills aluminum?
High-speed steel (HSS) works fine for occasional aluminum work. For longer life on thicker alloys, upgrade to M2 HSS (which has 50% more tungsten and 150% more molybdenum than standard HSS) or M35 cobalt steel, which resists heat buildup.
Can I use a wood drill bit on aluminum?
You can, but the cutting geometry is wrong — wood bits have a sharper point angle that can grab aluminum and cause a rough hole. A 135° split-point bit designed for metal self-centers without walking and leaves a cleaner cut.
Should I use a step bit or a twist bit on aluminum?
Use a step bit for thin sheet metal or enclosures where you need multiple hole sizes from one tool. Use a twist bit for deep holes in thick aluminum plate because the spiral flutes evacuate chips better than straight step grooves.
Do I need a pilot hole for a step bit?
Most step bits with a split-point tip (like all picks in this guide) are self-starting and do not require a pilot hole. The split point bites into the aluminum without walking across the surface.
What lubricant should I use when drilling aluminum?
Cutting oil or WD-40 works well — it reduces friction and prevents aluminum from galling (sticking to the bit edges). For very thin sheet, a quick spray of cutting fluid before each hole keeps the cut clean.
How do I keep aluminum from sticking to my drill bit?
Use a sharp bit with polished flutes, run your drill at a moderate speed (around 3000 RPM for small bits, slower for larger), and apply cutting oil. If chips still clog, back the bit out periodically to clear the flutes.
What is the difference between titanium-coated and cobalt bits for aluminum?
Titanium coating reduces friction and resists rust, making it easier for chips to slide off — good for clean aluminum drilling. Cobalt steel (like M35) is harder throughout the metal itself, so it lasts longer in production use but costs more.
Can I drill stainless steel with the same bit I use for aluminum?
You can if the bit is M2 HSS or cobalt steel — those materials handle the heat and hardness of stainless. Basic HSS step bits will dull quickly on stainless compared to aluminum.
How long do step drill bits last on aluminum?
With proper lubrication and moderate feed pressure, a quality M2 or cobalt step bit can drill hundreds of holes through thin aluminum before needing sharpening. The GMTOOLS M35 four-flute bit reportedly drilled 200+ hooks without dulling, per one verified buyer.
Is a four-flute step bit better than a two-flute for aluminum?
A four-flute bit cuts faster and leaves a smoother finish because there are more cutting edges engaging the aluminum. However, two-flute bits are easier to sharpen and less prone to clogging on very thin, gummy aluminum sheet.

Final Thoughts: The Verdict

For most people, the bit for drilling aluminum winner is the M2 HSS Quick Change 1/4″-3/4″ Step Drill Bit because it survives heavy stainless and steel while offering a quick-change hex shank (a six-sided grip for fast swaps) and polished step markings. If you want the widest size range from a single bit, grab the Jerax 3/16″-7/8″ M2 Step Bit. And for budget-friendly aluminum sheet work, the Jerax HS 1/8″-1/2″ Step Bit punches well above its price.

How We Picked

We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.

Sources & Methodology

Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of July 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.

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Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product. As an Amazon Associate I earn from qualifying purchases.

CERTAIN CONTENT THAT APPEARS ON THIS SITE COMES FROM AMAZON. THIS CONTENT IS PROVIDED "AS IS" AND IS SUBJECT TO CHANGE OR REMOVAL AT ANY TIME.

Amazon and the Amazon logo are trademarks of Amazon.com, Inc. or its affiliates.