Best Drill Bits for Metal: Top Picks for Steel, Stainless Steel, and Aluminum

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The best drill bits for metal depend on the material you’re drilling. Cobalt drill bits are the strongest general recommendation for frequent steel and stainless steel work, while titanium nitride (TiN)-coated high-speed steel (HSS) bits are a practical choice for routine drilling in mild steel and aluminum. For enlarging holes in thin sheet metal, a step drill bit can be more useful than a conventional twist bit.

For most homeowners and DIY users, a quality HSS or titanium-coated set is sufficient for occasional metalworking. If you regularly drill stainless steel, thicker steel stock, or harder alloys, consider cobalt bits with a 135-degree split point. For hardened tool steel, ordinary drill bits—including many cobalt sets—may not be suitable without confirming the material’s hardness and the bit manufacturer’s application guidance.

This guide compares established metal-drilling options, explains their trade-offs, and identifies which type makes sense for different projects. The recommendations are based on published product specifications and available independent comparisons, not on claims of personal testing.

Best Drill Bits for Metal at a Glance

Quick recommendation: Choose a cobalt set for frequent steel drilling, a titanium-coated HSS set for lighter work, and a step bit when you primarily need clean, larger holes in thin sheet metal. No single bit type is best for every metal.

1. DEWALT ELITE SERIES Cobalt PILOT POINT — Best Overall

Model: DWAMDCE29SET · 29-piece set

The DEWALT ELITE SERIES cobalt set is a strong all-around choice for DIYers and tradespeople who regularly drill steel, stainless steel, and other hard metals. Its combination of cobalt-alloy construction, jobber-length bits, and starting-point geometry makes it suitable for a wide range of common metalworking tasks.

Verified specifications

• Bit material: Cobalt-alloy steel.
• Set size: 29 pieces.
• Size range: 1/16 to 1/2 inch.
• Design: PILOT POINT tips on sizes above 5/16 inch; three-flat shanks on sizes 3/16 inch and larger.
• Power-tool compatibility: Standard drill chuck, provided the shank and drill capacity are suitable.

The manufacturer describes the set as intended for stainless steel and other hard metals. Its published comparison claims up to twice the life of a specified Milwaukee competitor in selected sizes under stated test conditions. That is a manufacturer claim, not evidence that it will last twice as long in every metal or application.

Advantages

• Wide fractional-size selection for repairs, fabrication, and maintenance.
• Cobalt-alloy construction suited to demanding metal drilling.
• Designed to reduce walking when starting holes.
• Multiple sizes for both small pilot holes and larger openings.

Limitations

• More expensive than many basic HSS sets.
• A 29-piece set may be unnecessary for occasional drilling.
• Cobalt bits can still overheat, dull, or break if used with unsuitable speed, feed, or workholding.

Buy if: You frequently drill different hole sizes in steel or stainless steel and want one comprehensive set.

Skip if: You mainly make occasional holes in thin aluminum or mild steel and want to minimize accessory costs.

2. Milwaukee RED HELIX Cobalt — Best for Frequent Metal Drilling

Example individual bit: 48-89-2321 · 3/8 inch

Milwaukee RED HELIX cobalt bits are worth considering for regular workshop and maintenance jobs involving hard metals. Their variable-helix flute geometry is designed to remove chips efficiently, while the 135-degree split point helps the bit start accurately.

Verified specifications

• Bit material: Cobalt-alloy steel.
• Tip: 135-degree split point with Milwaukee’s QUAD EDGE design.
• Flute design: Variable helix, with a stated angle transitioning from 35 degrees to 15 degrees.
• Shank: Three-flat Secure-Grip design on the cited 3/8-inch model.
• Applications: Hard metal, stainless steel, PVC, and wood, according to the manufacturer.

The reinforced web is intended to improve durability, and the flute design helps move chips out of the hole. These are useful design features, but they do not remove the need to control heat and feed pressure when drilling metal.

Milwaukee advertises up to 15 times the life of black-oxide bits for certain RED HELIX products. Treat that as a manufacturer comparison, not a universal service-life guarantee.

Advantages

• Split-point geometry helps reduce wandering at startup.
• Flute design supports chip evacuation.
• Suitable for demanding metal-drilling work.
• Individual replacement sizes can be practical if you repeatedly use a small number of diameters.

Limitations

• Premium features may not justify the cost for occasional home repairs.
• Individual-bit specifications do not establish the exact contents of every set.
• A cobalt bit is not automatically suitable for every hardened alloy.

Buy if: You drill steel regularly and value individual replacement options and purpose-designed cutting geometry.

Skip if: Your projects rarely involve metal or you mostly drill soft aluminum and thin sheet.

3. Bosch M42 Cobalt CO14B — Best Value-Oriented Cobalt Set

Model: CO14B · 14-piece set

The Bosch CO14B is a useful option for buyers who want a cobalt set without purchasing a large assortment. Bosch identifies this model as a cobalt M42 drill-bit set intended for metal drilling, including work in stainless steel.

M42 is a high-speed-steel grade containing approximately 8% cobalt in typical formulations. Its higher hardness and hot-hardness characteristics can help maintain cutting performance under heat, although the harder material is also more brittle than some lower-cobalt alternatives.

Verified specifications

• Bit material: M42 cobalt high-speed steel.
• Set size: 14 pieces.
• Size range: 1/16 to 1/2 inch.
• Included sizes: Common fractional sizes, with a duplicate 1/8-inch bit.
• Power-tool compatibility: Suitable for a compatible standard drill chuck; check the selected bit’s shank and your drill’s capacity.

Advantages

• M42 construction for demanding metal drilling.
• Useful range of common fractional sizes.
• Compact assortment for a home workshop or maintenance kit.
• Cobalt bits can be resharpened correctly because the cutting material extends through the bit.

Limitations

• Fewer pieces than a 29-piece set.
• Harder M42 bits require care to avoid snapping, particularly in smaller diameters.
• No verified current price is quoted here.

Buy if: You want a compact cobalt set for regular steel and stainless-steel projects.

Skip if: You need many duplicate sizes or frequently drill unusually large holes.

4. Drill America D/A Series M42 Cobalt — Best for Demanding Metalworking

Drill America’s D/A Series M42 cobalt bits are an option for users who prioritize cutting performance in harder metals and stainless steel. Independent testing published by Pro Tool Reviews selected this series for its hardened-metal and stainless-steel category.

The reviewed bits use M42 cobalt steel and a 135-degree split point. The split-point geometry helps the bit engage the material without wandering as much as a conventional blunt-point design.

What makes it suitable?

• M42 cobalt construction is intended for demanding metal drilling.
• A 135-degree split point helps with accurate starts.
• Cobalt-alloy bits can be resharpened when their cutting edges become dull.
• Individual sizes may make sense for workshops that repeatedly drill specific diameters.

Advantages

• A strong candidate for stainless steel and other demanding metal applications.
• Split-point geometry supports controlled hole starting.
• Useful when cutting performance matters more than buying the largest assortment.

Limitations

• M42 bits are relatively brittle and can break if twisted sideways or overloaded.
• Not every hardened steel workpiece is drillable with an ordinary twist bit.
• Independent test results apply to the tested configuration and conditions, not every size or every metal.

Buy if: You regularly work with stainless steel or harder alloys and can control drilling speed, feed, and workpiece movement.

Skip if: You are learning basic DIY metalworking and mainly drill thin, soft materials.

5. DEWALT Titanium PILOT POINT DW1369 — Best for Everyday DIY

Model: DW1369 · 29-piece set

For occasional holes in mild steel, aluminum, and other common materials, a titanium nitride-coated HSS set can be more economical than a cobalt set. The DEWALT DW1369 uses titanium nitride-coated bits with PILOT POINT geometry intended to help start holes accurately.

The important distinction is that titanium nitride is a surface coating, not a solid titanium cutting material. It can improve surface wear and reduce friction, but the underlying HSS determines much of the bit’s performance once the coating wears from the cutting edges.

Verified specifications

• Bit type: Titanium nitride-coated drill-bit set.
• Set size: 29 pieces.
• Intended applications: Metal and wood drilling.
• Design: PILOT POINT tips, no-spin shank features, and a tapered web, as described by DEWALT.

Advantages

• Practical for everyday home-repair jobs.
• Suitable for a broad range of routine drilling applications.
• Starting-point geometry helps reduce bit wandering.
• A sensible alternative to cobalt when hard-metal drilling is uncommon.

Limitations

• Not the preferred choice for frequent stainless-steel or hardened-steel drilling.
• Sharpening removes coating from the cutting edge, reducing one of the coating’s main benefits.
• Coated HSS bits can still overheat and lose cutting performance.

Buy if: Your projects mainly involve mild steel, aluminum, plastic, and occasional wood drilling.

Skip if: You routinely drill stainless steel or need a bit for a particularly hard workpiece.

6. IRWIN Cobalt Alloy Steel Drill Bits — Best for Resharpening

IRWIN cobalt-alloy steel drill bits are a sensible choice for people who want cutting edges that can be restored instead of replacing a bit whenever it becomes dull. IRWIN’s published support documentation identifies its cobalt bits as M35 cobalt steel containing 5% cobalt.

Unlike titanium nitride-coated HSS, cobalt bits use an alloy throughout the cutting material. Correctly resharpening a cobalt bit therefore does not remove its cobalt-alloy composition.

Why choose M35 cobalt?

• Good balance: M35 is a useful choice for repeated metal drilling without moving to the harder, more brittle M42 grade.
• Resharpening: A properly reground cutting edge retains the underlying alloy’s material properties.
• Broad application: Appropriate for many steel and stainless-steel drilling tasks when the workpiece hardness and drilling conditions are suitable.

Advantages

• Solid cobalt-alloy construction rather than a thin surface coating.
• Can be resharpened by someone with the appropriate equipment and technique.
• Practical for users who repeatedly use the same bit sizes.

Limitations

• Resharpening requires correct cutting-edge geometry.
• M35 is not a universal solution for extremely hard or heat-treated steel.
• Verify the exact IRWIN model before purchasing: the brand sells multiple bit materials, sizes, and set configurations.

Buy if: You maintain a workshop and prefer to resharpen frequently used bits.

Skip if: You only need a few holes for a one-time project and would rather buy a small, inexpensive set.

7. DEWALT Titanium Nitride Step Drill Bit — Best for Thin Sheet Metal

A step drill bit is often the better choice when making larger holes in thin metal panels, electrical enclosures, and sheet-metal components. Instead of using a separate twist bit for every diameter, one step bit can create multiple hole sizes within its specified range.

DEWALT’s titanium nitride-coated drilling accessories include step-style products, but the correct model must be selected for the required diameter range, material thickness, and drill compatibility. Do not assume every DEWALT titanium-coated set contains a step bit; DW1369, for example, is a conventional twist-bit set.

When a step bit makes sense

• Enlarging holes in thin sheet metal.
• Making openings for compatible fittings or cable glands.
• Creating several hole diameters without changing bits repeatedly.
• Working with suitable thin aluminum or mild-steel panels.

Advantages

• Multiple hole diameters from one accessory.
• Useful for controlled hole enlargement in thin material.
• Can reduce the need to carry numerous individual bit sizes.

Limitations

• Not a replacement for a conventional twist bit when drilling deep holes in thick stock.
• Maximum material thickness and diameter range depend on the exact model.
• Excessive pressure or unsuitable speed can damage the cutting edges or distort thin sheet metal.

Buy if: You frequently make different-sized openings in thin sheet metal.

Skip if: You mainly drill deep holes through thick steel bars, plates, or structural sections.

How to Choose the Best Drill Bits for Metal

The right bit depends on four factors: material hardness, hole diameter, material thickness, and how frequently you drill. Match those factors before comparing coatings, piece counts, or brand names.

1. Choose the right bit material

A higher-performance material is not always the best purchase. For a few holes in aluminum, a good HSS bit may be entirely adequate. For repeated stainless-steel drilling, a cobalt bit is usually the more appropriate investment.

2. Understand the drill-point angle

The point geometry affects how a bit engages the workpiece.

• 118-degree point: A common general-purpose geometry used for many standard twist bits.
• 135-degree split point: Common on metal-drilling bits, particularly cobalt models. It helps the bit start accurately and reduces walking.
• PILOT POINT-style designs: Use a shaped tip intended to improve starting behavior and hole quality; the precise geometry varies by manufacturer and model.

A split point can reduce wandering, but it does not eliminate the value of marking the hole accurately. For demanding work, use an appropriate center punch when recommended for the material and bit design.

3. Match the bit diameter to the hole

Use the diameter specified for the finished hole or the fastener’s recommended clearance. If drilling a larger hole, a smaller pilot hole may be useful depending on the bit, material, and operation.

For larger holes, consider whether a step bit, hole saw rated for the material, or another purpose-built cutter is more appropriate. Check the accessory’s permitted material, diameter, shank, and operating limits before use.

4. Check shank and drill compatibility

Most conventional twist bits with round or three-flat shanks fit suitable standard drill chucks. Some accessories use hex shanks designed for quick-change holders.

Before buying, confirm:

• The shank fits your drill or chuck.
• The bit diameter is within the drill’s chuck capacity.
• The accessory is rated for the intended material and operation.
• The drill can operate at a suitable speed for that bit and workpiece.

Do not assume that a bit designed for a standard drill is automatically appropriate for an impact driver, rotary hammer, or another specialized tool. Follow the accessory and tool manufacturers’ instructions.

How to Drill Metal Without Ruining Your Bits

Correct technique can matter as much as the bit material. Excessive heat, poor workholding, and sideways force can shorten bit life or cause breakage.

Use this checklist for ordinary metal drilling; follow the specific tool and accessory instructions whenever they differ.

1. Secure the workpiece. Clamp the metal to a stable work surface. Never rely on your hand to hold a small metal part against the drill’s rotational force.
2. Mark the hole. Measure and mark the intended center. Use a suitable center punch when appropriate to help prevent the bit from wandering.
3. Select the right bit. Match the bit material and diameter to the metal. For unknown or heat-treated alloys, establish the material and hardness before proceeding.
4. Set an appropriate speed. Metal-drilling speed depends on the bit diameter, workpiece material, and cutting conditions. Larger bits generally require lower rotational speeds than smaller bits in the same material. Consult the bit manufacturer’s guidance instead of using one universal RPM.
5. Use suitable cutting fluid. A metalworking lubricant or cutting fluid can help reduce friction and heat when appropriate for the material and operation. Follow the fluid manufacturer’s guidance.
6. Apply controlled feed pressure. Maintain steady pressure that allows the cutting edges to form chips. Avoid forcing a dull bit or allowing it to spin without cutting.
7. Clear chips safely. Stop the drill before clearing accumulated chips. Never remove swarf with bare fingers while the tool or workpiece is moving.
8. Control breakthrough. Reduce feed pressure as the bit approaches the far side of the workpiece. This helps reduce grabbing and sudden movement.
9. Inspect the hole and bit. Stop if the bit becomes dull, damaged, discolored from excessive heat, or begins cutting abnormally.

Essential safety precautions

• Wear appropriate eye protection against flying metal chips. Use additional protective equipment where the task requires it.
• Secure the workpiece and keep hands away from rotating components.
• Tie back long hair and avoid loose clothing, jewelry, or gloves that could become entangled in rotating machinery.
• Remove or secure the drill’s chuck key before starting.
• Use appropriate guarding and follow the tool manual’s instructions.
• Stop the tool and disconnect its power source before changing bits or making adjustments.
• Treat hot chips and the workpiece as burn hazards.

For overhead, industrial, or specialized drilling, assess the additional hazards and follow the applicable safety procedures. Ordinary twist-bit guidance should not be substituted for instructions governing specialized equipment.

Common Mistakes When Buying Metal Drill Bits

Buying titanium-coated bits for every metal: A coating does not make ordinary HSS suitable for every hard alloy. Choose the core material for the job.

Assuming cobalt means unbreakable: Cobalt bits can still snap, particularly when a small bit is overloaded or subjected to sideways force.

Choosing a set by piece count alone: A 29-piece set is not necessarily better than a 14-piece set if it lacks the sizes you actually use.

Ignoring the workpiece hardness: Heat-treated steel and hardened fasteners may be beyond the capabilities of ordinary twist bits. Verify suitability before drilling.

Using excessive speed: Heat can dull a bit and, with some materials such as stainless steel, poor technique can contribute to work-hardening. Follow material- and bit-specific cutting guidance.

Ignoring hole geometry: A step bit may be ideal for thin sheet metal but unsuitable for a deep hole through thick stock. Choose the cutter for the actual operation.

Frequently Asked Questions

What are the best drill bits for metal?

Cobalt-alloy HSS bits are an excellent choice for frequent steel and stainless-steel drilling, while titanium-coated HSS bits suit many routine DIY jobs. The best option depends on material hardness, hole size, and how often you drill.

Are cobalt drill bits better than titanium drill bits?

Cobalt bits are generally preferable for repeated drilling in stainless steel and demanding metals, while titanium nitride-coated HSS bits can offer good value for routine work in softer metals. Cobalt describes the alloy, whereas titanium nitride describes a surface coating.

Can you drill hardened steel with cobalt drill bits?

Sometimes, but not all hardened steel can be drilled successfully with ordinary cobalt twist bits. The workpiece’s actual hardness, heat treatment, bit specification, and drilling method determine whether the operation is feasible. If the material is too hard, use a suitable specialized process or seek qualified machining advice.

Should you use cutting oil when drilling metal?

Cutting oil or another suitable cutting fluid can help reduce friction and heat during many metal-drilling operations. Choose a fluid appropriate for the workpiece and tool, and follow the manufacturers’ instructions; do not assume every material or operation requires the same lubricant.

Final Verdict: Which Metal Drill Bits Should You Buy?

For most people who regularly drill steel and stainless steel, the DEWALT ELITE SERIES cobalt set DWAMDCE29SET is a strong all-around choice because it combines cobalt-alloy construction, a broad range of sizes, and features designed to help start holes accurately.

If you want a smaller cobalt assortment, consider the Bosch M42 CO14B. For demanding metalworking, the Drill America D/A Series M42 is worth considering based on independent testing. For occasional home repairs in softer metals, the DEWALT DW1369 titanium nitride-coated HSS set is a more practical alternative. If your main task is creating larger holes in thin sheet metal, choose a compatible step drill bit instead.

Before purchasing, verify the exact model, included sizes, and current availability. Match the bit to the metal rather than choosing solely by brand, coating color, or advertised piece count. With the right bit, appropriate speed, controlled pressure, and secure workholding, you can improve hole quality while reducing unnecessary wear and breakage.

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