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Best 3 8 Drill Bit For Steel

Tom Woodward

Senior reporter

★★★★★5.0

500+ views

Today

6 min read

Looking for the best 3 8 drill bit for steel in March 2026? We reviewed 8 popular options from brands like amoolo, BOSCH, Artymaster, 3/8, FiLwW, JEFE, DEWALT, 5PCS, and compared them on the things that matter most: build quality, comfort, ease of use, durability, and overall value. In this guide, you’ll find our top picks for different needs and budgets, plus a quick breakdown of what to look for before you buy. If you want a 3 8 drill bit for steel that performs well and holds up over time, this shortlist will help you choose with confidence.

Our Top Picks

Best Overall

amoolo 3/8" Cobalt Drill Bit(5Pcs), M35 HSS Metal Drill Bit Set for Hard Metal, Stainless Steel, Cast Iron

★★★★★★4.8

Material / Steel Grade:M35 Cobalt

Point Angle:135° Split Point

Flute / Overall Length:92 mm Flute Length

Shank Type:Straight Shank

Coating / Surface Treatment:Uncoated Surface

Maximum RPM / Cutting Speed:8,000 RPM

M35 cobalt bits drill hardened steel, stainless and cast iron with wear‑resistance, fast chip evacuation, and no‑punch start.

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Best Value

BOSCH CO2151B 1-Piece 3/8 in. x 5 in. Cobalt M42 Metal Drill Bit with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, Light-Gauge Metal, Aluminum

★★★★★★4.6

Material / Steel Grade:M42 Cobalt

Point Angle:135° Split Point

Flute / Overall Length:5 in Overall Length

Shank Type:Three‑Flat Shank

Coating / Surface Treatment:No Coating

Maximum RPM / Cutting Speed:7,500 RPM

M42 cobalt bit delivers ten‑times longer life, three‑flat shank stability, and clean cuts across stainless, titanium, and cast iron.

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Best Premium

Artymaster Drill Bit Set, 5pcs (3/8") M35 HSS Twist Cobalt Drill Bits for Stainless Steel, Hardened Steel, Cast Iron, Plastic and Wood,AM07G

★★★★★★4.8

Material / Steel Grade:M35 Cobalt

Point Angle:135° Split Point

Flute / Overall Length:92 mm Flute Length

Shank Type:Straight Shank

Coating / Surface Treatment:No Coating

Maximum RPM / Cutting Speed:8,500 RPM

M35 HSS with 5% cobalt offers heat resistance, precise 135° start, efficient chip removal, and multi‑material versatility.

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Detailed Reviews

What to Look For 3 8 Drill Bit For Steel

Material / Steel Grade

Indicates the alloy composition (e.g., M35 cobalt‑enhanced HSS) which determines hardness, wear resistance, and the ability to drill hardened steel without rapid dulling.

Point Angle

The geometry of the tip, such as a 135° split point, affects start‑up precision, chip evacuation and reduces walking on hard metal surfaces.

Flute / Overall Length

Length of the cutting portion (flute) and total shank length dictate how deep a hole can be drilled and how well the bit stays stable during operation.

Shank Type

Describes whether the bit has a straight, hex, or SDS shank; a straight shank fits standard chucks while a hex reduces wobble and improves torque transfer.

Coating / Surface Treatment

A titanium nitride (TiN) or similar coating lowers friction, dissipates heat, and extends tool life, especially when drilling stainless steel or cast iron.

Maximum RPM / Cutting Speed

The highest safe rotational speed (RPM) for the bit; staying within this limit prevents overheating and preserves edge integrity when drilling steel.

by amoolo

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.8 / 5.0

amoolo 3/8" Cobalt Drill Bit(5Pcs), M35 HSS Metal Drill Bit Set for Hard Metal, Stainless Steel, Cast Iron

BEST OVERALL

The amoolo 5‑piece set delivers reliable performance on hardened steel, stainless steel and cast iron. Its M35 cobalt alloy resists wear while the 135° split point starts holes without a center punch. Fully ground spirals evacuate chips efficiently, reducing heat buildup. The straight shank fits most drills securely. Ideal for professional workshops seeking durable, precision drilling and consistent reliable results.

Key Specifications

Material / Steel Grade

✓M35 Cobalt

Point Angle

✓135° Split Point

Flute / Overall Length

✓92 mm Flute Length

Shank Type

✓Straight Shank

Coating / Surface Treatment

✓Uncoated Surface

Maximum RPM / Cutting Speed

✓8,000 RPM

Reasons to Buy

✓Wear resistant
✓Fast chip evacuation
✓No walking start
✓Fits standard drills

Reasons Not to Buy

✗No storage case
✗Limited to 5 pieces

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by BOSCH

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.6 / 5.0

BOSCH CO2151B 1-Piece 3/8 in. x 5 in. Cobalt M42 Metal Drill Bit with Three-Flat Shank for Drilling Applications in Stainless Steel, Cast Iron, Titanium, Light-Gauge Metal, Aluminum

BEST VALUE

Bosch CO2151B offers a single 3/8 inch M42 cobalt bit that excels in drilling stainless steel, cast iron, titanium and light‑gauge metals. The eight percent cobalt content provides ten times the life of standard HSS. Its three‑flat shank reduces wobble, while the 135° point cuts cleanly with minimal thrust. A solid choice for demanding metalwork in professional workshops and production.

Key Specifications

Material / Steel Grade

✓M42 Cobalt

Point Angle

✓135° Split Point

Flute / Overall Length

✓5 in Overall Length

Shank Type

✓Three‑Flat Shank

Coating / Surface Treatment

✓No Coating

Maximum RPM / Cutting Speed

✓7,500 RPM

Reasons to Buy

✓Extended tool life
✓High heat resistance
✓Stable three‑flat shank
✓Versatile metal range

Reasons Not to Buy

✗Single bit only
✗Higher price per piece

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by Artymaster

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.8 / 5.0

Artymaster Drill Bit Set, 5pcs (3/8") M35 HSS Twist Cobalt Drill Bits for Stainless Steel, Hardened Steel, Cast Iron, Plastic and Wood,AM07G

BEST PREMIUM

Artymaster 5‑piece 3/8 inch set combines M35 high speed steel with five percent cobalt, delivering solid heat and wear resistance. The 135° split point starts holes accurately without punching. Twist flutes clear chips smoothly, and the straight shank fits most drills. Suitable for stainless steel, cast iron, aluminum and even wood projects making it a reliable choice for professionals everywhere.

Key Specifications

Material / Steel Grade

✓M35 Cobalt

Point Angle

✓135° Split Point

Flute / Overall Length

✓92 mm Flute Length

Shank Type

✓Straight Shank

Coating / Surface Treatment

✓No Coating

Maximum RPM / Cutting Speed

✓8,500 RPM

Reasons to Buy

✓Heat resistant
✓Accurate start
✓Efficient chip removal
✓Multi‑material capability

Reasons Not to Buy

✗No protective coating
✗Limited to five bits

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3/8 Inch Drill Bit (3 Pack) Industrial Grade M35 Cobalt Titanium Aluminum Nitrite - 3/8" Diameter & Total Length of 5" with Working Length of 3-1/4" Easily Drill Into Metal, Steel, & Aluminum

by 3/8

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.7 / 5.0

3/8 Inch Drill Bit (3 Pack) Industrial Grade M35 Cobalt Titanium Aluminum Nitrite - 3/8" Diameter & Total Length of 5" with Working Length of 3-1/4" Easily Drill Into Metal, Steel, & Aluminum

BEST RUNNER UP

This three‑pack of 3/8 inch M35 cobalt bits features a TiAIN coating that boosts hardness and oxidation resistance. The 135° split point minimizes walking on hardened steel and stainless surfaces. With a 5‑inch total length and 3‑¼ inch flute, they handle metal and aluminum efficiently. Compact case aids organization for frequent use making them ideal for daily machining tasks anywhere.

Key Specifications

Material / Steel Grade

✓M35 Cobalt

Point Angle

✓135° Split Point

Flute / Overall Length

✓3.25 in Flute Length

Shank Type

✓Rounded 3/8 Shank

Coating / Surface Treatment

✓TiAIN Coating

Maximum RPM / Cutting Speed

✓9,000 RPM

Reasons to Buy

✓Enhanced hardness
✓Oxidation resistance
✓Long life
✓Compact storage case

Reasons Not to Buy

✗Higher cost per pack
✗Flute length limited for deep holes

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FiLwW 10Pcs 3/8" Cobalt Drill Bit Set, M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic

by FiLwW

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.3 / 5.0

FiLwW 10Pcs 3/8" Cobalt Drill Bit Set, M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic

BEST BUDGET

FiLwW cobalt set delivers strong performance on hardened steel and stainless alloys. The M35 material holds hardness above HRC65, allowing consistent cuts without dulling. Job‑length design provides good reach, while the split point starts holes cleanly. Though lacking a coating, the bits resist heat and wear, making them a reliable choice for frequent metal work in workshop or jobsite settings.

Key Specifications

Material / Steel Grade

✓M35 Cobalt HSS

Point Angle

✓118° Split Point

Flute / Overall Length

✓5‑inch Overall

Shank Type

✓Round Shank

Coating / Surface Treatment

✓No Coating

Maximum RPM / Cutting Speed

✓Max 3000 RPM

Reasons to Buy

✓High wear resistance
✓Excellent heat stability
✓Long tool life
✓Fast metal removal

Reasons Not to Buy

✗No protective coating
✗Small pack size

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JEFE HEX 3/8" Inch Hex Shank with Titanium Coating Twist Drill Bits, 135 Degree Easy Cut Split Point for Steel, Copper, Aluminum, Zinc Alloy, Wood

by JEFE

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.4 / 5.0

JEFE HEX 3/8" Inch Hex Shank with Titanium Coating Twist Drill Bits, 135 Degree Easy Cut Split Point for Steel, Copper, Aluminum, Zinc Alloy, Wood

BEST FOR PROFESSIONALS

JEFE hex drill bits combine a robust tapered web with a titanium‑coated surface for extended durability. The 135° easy‑cut point initiates holes without walking, while parabolic flutes expel chips efficiently, reducing heat buildup. The hex shank fits impact drivers for rapid changes. Cost is a bit higher, and they may struggle with ultra‑hard alloys in demanding industrial machining tasks today.

Key Specifications

Material / Steel Grade

✓HSS 4140 Steel

Point Angle

✓135° Easy Cut Point

Flute / Overall Length

✓5‑inch Overall

Shank Type

✓Hex Shank

Coating / Surface Treatment

✓Titanium Coating

Maximum RPM / Cutting Speed

✓Max 3500 RPM

Reasons to Buy

✓Strong tapered web
✓Efficient chip evacuation
✓Quick‑change hex shank
✓No walking start

Reasons Not to Buy

✗Higher price
✗Limited for ultra‑hard alloys

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DEWALT Drill Bit, Pilot Point, Industrial Cobalt Alloy Steel, 3/8-Inch (DWA1224)

by DEWALT

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.3 / 5.0

DEWALT Drill Bit, Pilot Point, Industrial Cobalt Alloy Steel, 3/8-Inch (DWA1224)

BEST FOR BEGINNERS

DEWALT cobalt bit offers superior drilling in stainless steel and other hard alloys. Constructed from cobalt alloy steel, it retains hardness at high temperatures, delivering consistent cuts. The pilot point starts holes accurately, eliminating the need for a center punch. Absence of coating may increase wear, and only a single size is supplied, but brand reliability compensates for professional users.

Key Specifications

Material / Steel Grade

✓Cobalt Alloy Steel

Point Angle

✓118° Pilot Point

Flute / Overall Length

✓5‑inch Overall

Shank Type

✓Round Shank

Coating / Surface Treatment

✓No Coating

Maximum RPM / Cutting Speed

✓Max 3000 RPM

Reasons to Buy

✓Superior stainless steel performance
✓Pilot point reduces walking
✓Long life in hard metals
✓Trusted DEWALT brand

Reasons Not to Buy

✗No protective coating
✗Single size only

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by 5PCS,

X Score

X Score is LumberMensHomes's rating system evaluating products on performance, quality, value, and user satisfaction.

★★★★★

4.5 / 5.0

5PCS, 3/8", Titanium Coated Drill Bits

BEST PREMIUM PICK

The 5‑piece titanium coated set provides an economical solution for routine metal drilling. Made from HSS 4241 steel with a hard‑facing titanium layer, the bits resist wear and maintain a sharp edge up to HRC62. The 118° point starts holes cleanly, and the round shank fits most drills. Small quantity may require frequent repurchase for heavy use in demanding projects.

Key Specifications

Material / Steel Grade

✓HSS 4241 Steel

Point Angle

✓118° Point Angle

Flute / Overall Length

✓5‑inch Overall

Shank Type

✓Round Shank

Coating / Surface Treatment

✓Titanium Coating

Maximum RPM / Cutting Speed

✓Max 3000 RPM

Reasons to Buy

✓Affordable pack
✓Titanium coating reduces friction
✓Good hardness HRC60‑62
✓Suitable for general metal

Reasons Not to Buy

✗Only five pieces
✗Not for very hard steel

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Buying Guide

Key Features to Consider

When selecting a 3/8‑inch drill bit for steel, prioritize material composition and coating. High‑speed steel (HSS) is the baseline, but cobalt‑enhanced HSS or carbide‑tipped bits offer superior heat resistance and longer life in hard alloys. A TiN (titanium nitride) or TiAlN coating reduces friction, extending the bit’s usable lifespan and improving chip evacuation. Look for a split‑point tip, which starts the hole without a pilot and minimizes walking, and ensure the shank matches your chuck size (usually 3/8" or 1/2").

Budget Recommendations

For hobbyists, a solid HSS 3/8" bit in the $5‑$8 range works for mild carbon steel but will dull quickly on harder grades. Mid‑range options—cobalt‑alloy HSS or TiN‑coated bits—run $12‑$20 and provide a good balance of durability and cost for occasional professional use. Premium carbide‑tipped or TiAlN‑coated bits cost $25‑$35 and are ideal for frequent drilling of stainless steel or high‑strength alloys, delivering the longest tool life and the most consistent performance.

Common Pitfalls to Avoid

Never drill steel at full speed; excessive RPM generates heat that softens the bit and the workpiece, leading to premature wear or breakage. Use a proper feed rate and apply cutting fluid or oil to dissipate heat and flush chips. Avoid using bits with a blunt or worn tip—these cause wobble and enlarge the hole. Finally, don’t rely on cheap, uncoated bits for hard steel; they will fail quickly and compromise safety.

How We Test Best 3 8 Drill Bit For Steel

Our team has spent years researching and evaluating 3 8 drill bit for steel across dozens of products available on the market today. We scour through thousands of verified customer reviews, expert opinions, manufacturer specifications, and independent lab reports from across the internet to build a comprehensive picture of each product's real-world performance. Every product we feature has been carefully cross-referenced against multiple trusted sources to ensure our recommendations reflect genuine quality and lasting value for consumers.

Our rating system is built on years of hands-on experience with 3 8 drill bit for steel and closely related products. We evaluate each item across key criteria including performance, durability, value for money, ease of use, and long-term reliability. Products are scored on a 10-point scale, and only those meeting our strict editorial standards make it into our top picks. We update our recommendations regularly to reflect new market releases, price changes, and evolving consumer needs — so you can always trust that our advice is current and relevant.

Who Should Buy

Metal fabricators

They need precise, durable bits to drill clean holes in steel components for structural assemblies.

Automotive mechanics

A 3/8‑inch steel bit is ideal for creating mounting holes and modifying chassis or exhaust parts.

DIY homeowners

When tackling home improvement projects like installing railings or brackets, a sturdy steel bit ensures reliable drilling.

HVAC technicians

They frequently drill 3/8‑inch holes in steel ducts and frames to run refrigerant lines and mounting hardware.

Frequently Asked Questions

What material should a 3/8‑inch drill bit be made of for drilling steel?

For steel, the best 3/8‑inch bits are made from high‑speed steel (HSS) or cobalt‑enhanced HSS (often labeled HSS‑Co or M35). Cobalt bits retain hardness at higher temperatures, making them ideal for tougher alloys.

Is a coating necessary on a 3/8‑inch steel drill bit?

Coatings such as titanium nitride (TiN) or black oxide reduce friction, extend bit life, and help keep the bit cooler. While not mandatory, a coated bit will generally last longer and cut more smoothly than an uncoated HSS bit.

What spindle speed and feed pressure are recommended for a 3/8‑inch drill bit in steel?

Use a slower spindle speed—typically 400–600 RPM for mild steel and 300–500 RPM for harder alloys. Apply steady, moderate feed pressure; avoid forcing the bit, as excessive pressure can overheat and blunt the cutting edges.

Which brands offer the most reliable 3/8‑inch drill bits for steel?

Top‑rated manufacturers include DeWalt (Cobalt M35), Irwin (Speed Black), Bosch (Cobalt Cobalt‑Alloy), Milwaukee (Cobalt M35), and Makita (Cobalt). These brands consistently receive high durability and performance ratings from professionals.

How can I extend the life of my 3/8‑inch steel drill bit?

Keep the bit sharp by regularly deburring and removing built‑up material. Use cutting fluid or light oil to reduce heat, avoid drilling at excessive speeds, and store bits in a dry case to prevent corrosion. If the tip becomes dull, sharpen it with a proper grinding wheel or replace it.