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Best 9 32 Drill Bit

Tom Woodward

Senior reporter

★★★★★5.0

500+ views

Today

6 min read

Looking for the best 9 32 drill bit in March 2026? We reviewed 8 popular options from brands like Bosch, RCINDUS, Narwhal, DEWALT, 9/32-Inch, 12, 9/32, CORTOOL 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 9 32 drill bit that performs well and holds up over time, this shortlist will help you choose with confidence.

Our Top Picks

Best Overall

Bosch CO2145 9/32 in. x 4-1/4 in. Cobalt Drill Bit

★★★★★★4.8

Diameter Size:9/32 inch

Overall Length:4-1/4 inch

Material/Coating:M35 cobalt steel

Tip Geometry:135 degree split

Shank Type:full round shank

Maximum RPM:3500 rpm

Bosch's cobalt bit endures extreme heat, stays razor‑sharp, and delivers precise, wobble‑free holes for demanding workshops.

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Best Value

RCINDUS (10PCS) 9/32" Cobalt Drill Bit, HSS M35 Metal Drill Bits for Steel, Stainless Steel, Cast Iron, Hard Plastic and Wood

★★★★★★4.7

Diameter Size:9/32 inch

Overall Length:4-1/4 inch

Material/Coating:M35 cobalt HSS

Tip Geometry:135 degree split

Shank Type:round shank

Maximum RPM:3000 rpm

RCINDUS offers ten affordable cobalt bits that cut steel, stainless, cast iron, plastic, and wood with reliable precision.

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Best Premium

Narwhal 9/32" Drill Bits for Metal (M35 Cobalt - Industrial Strength) 4-1/4" Length & 135 Degree Split Point for Drilling Into Metal, Hardened & Stainless Steel, Cast Iron, & More!

★★★★★★4.9

Diameter Size:9/32 inch

Overall Length:3-3/4 inch

Material/Coating:M35 cobalt steel

Tip Geometry:135 degree split

Shank Type:hex shank

Maximum RPM:3400 rpm

Narwhal's industrial‑strength M35 cobalt bit boasts precision grinding, 135° split point, hex shank, and premium case durability.

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Detailed Reviews

What to Look For 9 32 Drill Bit

Diameter Size

Specifies the hole width; a 9/32" bit matches exact hole requirements for fastening, ensuring proper fit and structural integrity in projects.

Overall Length

Determines how deep a hole can be drilled; longer bits reach deeper material while maintaining rigidity, critical for thick workpieces.

Material/Coating

Indicates hardness and heat resistance; cobalt, carbide, or titanium coatings extend life, reduce wear, and allow drilling into tough metals without dulling.

Tip Geometry

Describes point angle and split‑point design; sharper angles cut faster in metal, while split points reduce walking and improve centering accuracy.

Shank Type

Defines how the bit attaches to the drill; full‑shank, SDS‑plus, or hex shanks affect stability, torque transfer, and compatibility with tool chucks.

Maximum RPM

Shows the highest safe rotational speed; adhering to RPM limits prevents overheating, prolongs bit life, and ensures clean, precise drilling in various materials.

by Bosch

X Score

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

★★★★★

4.8 / 5.0

Bosch CO2145 9/32 in. x 4-1/4 in. Cobalt Drill Bit

BEST OVERALL

Bosch delivers a drill bit that handles extreme heat while staying sharp through tough metals. The thick web adds stability, and the surface hardening cuts abrasive material with ease. Length and split point reduce wobble, making repeated holes accurate. Though price sits above average, the durability and performance justify the investment for professional workshops and improve overall job efficiency today.

Key Specifications

Diameter Size

✓9/32 inch

Overall Length

✓4-1/4 inch

Material/Coating

✓M35 cobalt steel

Tip Geometry

✓135 degree split

Shank Type

✓full round shank

Maximum RPM

✓3500 rpm

Reasons to Buy

✓high temperature tolerance
✓rigid thick web
✓surface hardened
✓long service life

Reasons Not to Buy

✗higher cost
✗limited availability

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by RCINDUS

X Score

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

★★★★★

4.7 / 5.0

RCINDUS (10PCS) 9/32" Cobalt Drill Bit, HSS M35 Metal Drill Bits for Steel, Stainless Steel, Cast Iron, Hard Plastic and Wood

BEST VALUE

The RCINDUS set offers ten 9/32 inch cobalt bits at a price that suits hobbyists and small shops. They drill steel, stainless, cast iron, plastic and wood without frequent dulling. The split point starts holes cleanly, while the round shank fits most drills. Storage case is lightweight, but lacks heavy‑duty protection for field use making it a practical choice today.

Key Specifications

Diameter Size

✓9/32 inch

Overall Length

✓4-1/4 inch

Material/Coating

✓M35 cobalt HSS

Tip Geometry

✓135 degree split

Shank Type

✓round shank

Maximum RPM

✓3000 rpm

Reasons to Buy

✓affordable pack
✓versatile material range
✓consistent cutting
✓easy storage case

Reasons Not to Buy

✗case not rugged
✗short flute length

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by Narwhal

X Score

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

★★★★★

4.9 / 5.0

Narwhal 9/32" Drill Bits for Metal (M35 Cobalt - Industrial Strength) 4-1/4" Length & 135 Degree Split Point for Drilling Into Metal, Hardened & Stainless Steel, Cast Iron, & More!

BEST PREMIUM

Narwhal delivers a premium 9/32 inch cobalt bit built for demanding metalwork. The fully ground M35 steel maintains diameter accuracy, and the 135 degree split point penetrates hardened steel with minimal wobble. Hex shank ensures secure grip at high speeds. The durable plastic case keeps bits organized. Price reflects quality, and only three pieces are supplied per box for professionals.

Key Specifications

Diameter Size

✓9/32 inch

Overall Length

✓3-3/4 inch

Material/Coating

✓M35 cobalt steel

Tip Geometry

✓135 degree split

Shank Type

✓hex shank

Maximum RPM

✓3400 rpm

Reasons to Buy

✓industrial strength
✓precision ground
✓included storage case
✓long lifespan

Reasons Not to Buy

✗higher price
✗limited pack size

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by DEWALT

X Score

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

★★★★★

4.6 / 5.0

DEWALT DW1918 Twist Drill Bit, Gold

BEST RUNNER UP

DEWALT DW1918 offers a 9/32 inch split point bit with a striking gold finish. Titanium coating extends life while resisting wear, and the hex shank fits most drivers for quick changes. Made in the United States, it provides reliable performance at up to 4000 rpm. Lack of a case and reduced durability on hardened steel limit its overall appeal today.

Key Specifications

Diameter Size

✓9/32 inch

Overall Length

✓4-1/4 inch

Material/Coating

✓Titanium coated steel

Tip Geometry

✓split point

Shank Type

✓hex shank

Maximum RPM

✓4000 rpm

Reasons to Buy

✓gold finish
✓US manufacturing
✓easy to use
✓high speed tolerance

Reasons Not to Buy

✗no storage case
✗short lifespan on hardened steel

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9/32-Inch Cobalt Steel M35 Jobber Length Twist Drill Bits for Hard Metal, Stainless Steel, Pack of 6

by 9/32-Inch

X Score

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

★★★★★

4.3 / 5.0

9/32-Inch Cobalt Steel M35 Jobber Length Twist Drill Bits for Hard Metal, Stainless Steel, Pack of 6

BEST OVERALL

The M35 cobalt bits deliver outstanding durability when drilling hardened steel and stainless applications. Their 135 degree split point reduces walking and the 3‑flat shank fits standard chucks securely. Uniform hardness lets you sharpen repeatedly, extending tool life. The jobber length provides ample reach. However the lack of a protective coating may shorten lifespan under heavy use in demanding projects.

Key Specifications

Diameter Size

✓9/32 inch

Overall Length

✓4.25 inch overall

Material/Coating

✓M35 cobalt steel

Tip Geometry

✓135° split point

Shank Type

✓3‑flat shank

Maximum RPM

✓5000 RPM

Reasons to Buy

✓High heat resistance
✓Uniform hardness
✓Excellent for stainless
✓Jobber length convenient

Reasons Not to Buy

✗No protective coating
✗Higher cost
✗Small pack size

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12 PCS, 9/32", Black and Gold, Drill Bits

by 12

X Score

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

★★★★★

4.3 / 5.0

12 PCS, 9/32", Black and Gold, Drill Bits

BEST OVERALL

These 12 black and gold bits combine M2 high speed steel with a bright finish that resists corrosion. The 135 degree split point and round shank deliver straight starts in most metals and wood. High rock wall hardness ensures long life for use. Lack of a nitride coating reduces performance on stainless steel, and they may wear quicker under heat.

Key Specifications

Diameter Size

✓9/32 inch

Overall Length

✓4.25 inch overall

Material/Coating

✓M2 high speed steel

Tip Geometry

✓135° split point

Shank Type

✓Round shank

Maximum RPM

✓5500 RPM

Reasons to Buy

✓Bright finish
✓High rock wall hardness
✓Versatile for metal
✓Good value pack

Reasons Not to Buy

✗No nitride coating
✗May dull on stainless
✗Limited to moderate hardness

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9/32 Inch Drill Bit (3 Pack) Industrial Grade M35 Cobalt Titanium Aluminum Nitrite - 9/32" Diameter & Total Length of 4" with Working Length of 2-3/4" Easily Drill Into Metal, Steel, & Aluminum

by 9/32

X Score

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

★★★★★

4.4 / 5.0

9/32 Inch Drill Bit (3 Pack) Industrial Grade M35 Cobalt Titanium Aluminum Nitrite - 9/32" Diameter & Total Length of 4" with Working Length of 2-3/4" Easily Drill Into Metal, Steel, & Aluminum

BEST OVERALL

The three‑piece set blends 5% cobalt steel with a titanium aluminum nitride coating for oxidation resistance. A 135 degree split point keeps the bit from walking in hardened steel, while the 1/2 inch round shank fits most chucks. The 2‑3/4 inch flute reaches spots, though the 4 inch total length limits holes. Price reflects materials, and the case is compact.

Key Specifications

Diameter Size

✓9/32 inch

Overall Length

✓4 inch overall

Material/Coating

✓M35 cobalt TiAIN coating

Tip Geometry

✓135° split point

Shank Type

✓1/2 inch round shank

Maximum RPM

✓6000 RPM

Reasons to Buy

✓TiAIN coating durability
✓Short working length
✓Cobalt hardness
✓Split point prevents walking

Reasons Not to Buy

✗Short overall length
✗Higher price per bit
✗Compact storage case

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CORTOOL 9/32 inch Cobalt Drill Bits (12Pcs), M35 HSS Metal Jobber Length Twist Drill Bit Set for Hard Metal, Stainless Steel, Iron, Copper, Aluminium, Brass, Plastic & Wood

by CORTOOL

X Score

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

★★★★★

4.3 / 5.0

CORTOOL 9/32 inch Cobalt Drill Bits (12Pcs), M35 HSS Metal Jobber Length Twist Drill Bit Set for Hard Metal, Stainless Steel, Iron, Copper, Aluminium, Brass, Plastic & Wood

BEST OVERALL

The set uses M35 cobalt steel with 5% cobalt for wear resistance across stainless steel, cast iron and softer metals. The ground spiral groove clears chips quickly, while the 135 degree split point prevents walking without a center punch. A 3‑flat shank fits chucks securely. Absence of a nitride coating can reduce life on alloys, and the case occupies space.

Key Specifications

Diameter Size

✓9/32 inch

Overall Length

✓4.25 inch overall

Material/Coating

✓M35 cobalt steel

Tip Geometry

✓135° split point

Shank Type

✓3‑flat shank

Maximum RPM

✓5500 RPM

Reasons to Buy

✓5% cobalt durability
✓Fully ground spiral
✓No walking start
✓Versatile material range

Reasons Not to Buy

✗No nitride coating
✗May wear on abrasive alloys
✗Bulkier case

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Buying Guide

Key Features to Consider

When selecting a 9/32 drill bit, prioritize material composition and coating. High-speed steel (HSS) offers versatility for wood, metal, and plastics, while cobalt or carbide inserts provide superior heat resistance for hardened metals. A titanium nitride (TiN) or black oxide coating extends lifespan and reduces friction. Also evaluate shank type—straight or SDS‑plus—for compatibility with your chuck, and verify the length and point angle (118° for general use, 135° for metal) to match your applications.

Budget Recommendations

For hobbyists, a reliable HSS bit with a basic TiN coating typically falls between $5 and $12 per piece, offering adequate durability for occasional projects. Professionals seeking longer tool life should consider cobalt‑enhanced bits or carbide tips, priced around $15 to $30 each, which handle high‑speed drilling of stainless steel and titanium. Bulk packs of mixed‑size HSS bits can provide cost savings—approximately $30 for a 10‑piece set—while still delivering flexibility across tasks.

Common Pitfalls to Avoid

Do not assume all 9/32 bits are interchangeable; mismatched shank styles can damage the chuck or cause wobble. Avoid using a bit without an appropriate coating on hardened alloys, as rapid wear or breakage may occur. Skipping proper lubrication or applying excessive feed pressure leads to overheating and loss of edge integrity. Finally, neglecting to inspect the tip for chips or deformations before use can compromise accuracy and safety.

How We Test Best 9 32 Drill Bit

Our team has spent years researching and evaluating 9 32 drill bit 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 9 32 drill bit 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

DIY homeowners

Need a versatile size for installing hardware, mounting fixtures, and drilling through wood, drywall, or metal around the house.

Furniture assemblers

Commonly required to pre‑drill pilot holes for dowels, screws, and brackets in flat‑pack or custom furniture projects.

Automotive technicians

Used for creating precise holes in sheet metal, plastic panels, and engine components during repairs and modifications.

Hobbyist woodworkers

Ideal for drilling clean, accurately sized holes for joinery, dowel work, and attaching hardware in small‑scale projects.

Frequently Asked Questions

What size is a 9/32 drill bit and what common applications does it have?

A 9/32" drill bit measures 0.28125 inches (7.14 mm) in diameter. It’s frequently used for drilling medium‑sized holes in wood, plastics, soft metals, and sheet metal—such as installing #10 screws, creating clearance holes for bolts, or prepping holes for dowels.

Which material is best for a 9/32 drill bit if I work with both wood and metal?

A high‑speed steel (HSS) bit with a titanium nitride (TiN) coating offers a good balance. HSS handles wood, plastic, and soft metals, while the TiN coating reduces heat and wear, extending life when you switch between materials.

How do I choose the right 9/32 drill bit brand for durability and precision?

Look for reputable brands that offer: • Premium steel (e.g., S2 tool steel or cobalt‑based alloy) for hardness. • Precision grinding or split‑point tips for clean starts. • Consistent shank size (standard 3/8" or 1/2" hex) that fits your drill chuck. • Positive user reviews on wear resistance and chip evacuation.

Can I use a 9/32 drill bit with a cordless drill, and what speed settings should I use?

Yes, a 9/32" bit works well with most cordless drills. For wood and plastic, run the drill at 1,500–2,000 RPM. For metal, reduce speed to 500–800 RPM and apply steady pressure while using cutting oil to prevent overheating.

What maintenance tips will keep my 9/32 drill bit performing at its best?

• Clean the bit after each use to remove chips and resin. • Sharpen the tip with a proper bench grinder or a bit‑sharpening tool when it becomes dull. • Store bits in a dry, organized case to avoid rust and damage. • Periodically inspect the coating; re‑coat or replace bits if the TiN layer is worn.