Top 50 Drill Bits for Hardened Steel: Precision and Power

Working with hardened steel presents unique challenges, particularly when it comes to drilling. This specialized equipment requires drill bits engineered specifically for penetrating steel that has been heat-treated to increase its hardness. Our handpicked selection features premium materials and advanced coatings designed to maximize durability and efficiency while minimizing wear.

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Drill America DWDN91P12 High-Speed Steel Drill Bit

This drill bit combines high-speed steel durability with black oxide treatment to excel in general-purpose applications across various materials. The round shank design offers versatile compatibility with popular toolholding systems, while the right-hand spiral fluted profile helps maintain chip evacuation during use.

Norseman 44170 Ultra Dex Drill Set

When you're working with tough materials like stainless steel, having the right tools can make or break your project. That's why these American-made drill bits are worth the investment – each one is precision-engineered to tackle even the hardest metals while maintaining razor-sharp edges. The special coating and heat treatment process make them last longer than cheaper alternatives, so you'll save time and money in the long run. Whether you're a professional mechanic or just someone who likes to tackle tough jobs around the house, these bits are built to perform.

Cobalt Drill Bits Set

This high-quality drill bit set combines durable cobalt steel construction with precise 135-degree split points for smoother drilling through hardened metals like stainless steel and cast iron. The fully ground spiral flute design efficiently removes chips and reduces heat, while the straight-shank construction prevents bit wandering for consistent results. The 19-piece metric set features jobber length bits ranging from 1mm to 10mm, each clearly marked on both the drill bit and storage case for quick identification.

Mulwark M35 Cobalt Drill Bit Set

This cobalt drill bit set from MulWark combines high-speed steel with titanium nitride coating for exceptional durability and reduced friction. The 15 pieces of 3/16-inch bits feature a spiral grooved design that enhances chip removal, while the 135-degree split point ensures precise starts. At just over 3 inches long with a 2-5/16 inch flute, these bits handle everything from wood and plastic to carbon fiber and stainless steel.

Grizzly G3658 Drill Bit Set

Crafted from high-speed steel with durable titanium nitride coating, this comprehensive drill bit set includes every size from 1/16" to 1/2". The indexed storage case keeps everything organized and secure, making it perfect for any toolbox or workshop. While some users have noted minor quality issues with specific bits, many still appreciate the set's affordability and completeness.

Caroller M35 Cobalt Drill Bit Set

These versatile M35 cobalt drill bits handle everything from stainless steel to cast iron, with a jobber length design that provides stability during drilling. The highspeed steel construction maintains its shape and durability even when working with tough materials like titanium alloy. To get the most out of your bits, keep them cool and don't forget your safety gear.

DRILLFORCE Titanium Coated Drill Bits

These titanium-coated twist drill bits are built for serious metalworking, combining 4241 high-speed steel construction with a rock-hard 60-62 HRC rating for exceptional durability. Each bit measures 27/64 inch in diameter and features a precision 135-degree tip design that cuts faster while maintaining perfect alignment. The compact 5-piece set, measuring just over 5 inches in length, comes packaged in a protective plastic sleeve for easy storage in any toolbox or vehicle.

Harden 610292 Roll Forged HSS Drill Bits

This handy metal storage box holds 19 precision-ground HSS drill bits, ranging from 1mm to 10mm, with their sizes clearly visible for easy selection. The drill bits, designed for use on steel, stainless steel, aluminum, copper, wood, and plastic, feature a durable 118-degree split point and have been heat-treated for extra strength.

COMOWARE Cobalt Drill Bit Set

This comprehensive drill bit set combines durable HSS M35 material with 5% cobalt for exceptional performance on tough materials. The precision 135-degree split point and spiral flutes excel at chip clearance, while the organized storage holder keeps your set tidy and sortable.

Drill America KFDML1/2 HSS Drill Bit

Made from high-speed steel, these 1/2-inch drill bits combine a durable 135° split point with a 3-flat shank design for secure chuck grip. The black and gold surface treatment makes them particularly effective for drilling in stainless steel and other hard materials. Users appreciate their self-centering capabilities and reliable performance in both wood and metal.

Drill America D/aco68 Cobalt Drill Bit

These premium cobalt drill bits deliver exceptional performance for tough materials like stainless steel and titanium, thanks to their hardened alloy construction that maintains sharpness far longer than conventional bits. The jobber length design with a 135-degree split point reduces drilling effort while maintaining precise hole accuracy. Constructed to aerospace standards, these American-made bits combine durability with practical features like a reduced shank for hand drill compatibility.

Triumph Twist Drill Bit Set

Made in America, this 29-piece drill bit set handles everything from aluminum to wood with its high-speed steel construction and 118-degree point. The jobbers-length drills feature a handy 1/16 to 1/2 inch by 64ths scaling for precise measurements. The bright finish helps clear out chips in softer materials, making it a practical choice for DIY projects and general maintenance.

Precision Twist Drill Bits

This extra length drill bit pairs a generous 29/64-inch diameter with a 13-inch flute for tackling tough materials. The high-speed steel construction and bright finish ensure it cuts through hardened steel with precision, while its 18-inch overall length makes it stand out in any toolbox.

Triumph Twist Drill Bit Set

Made in the USA, these high-speed steel drill bits combine durability with practical features like a 118-degree point and precise 1/64 inch step increments. The bright, uncoated design excels in drilling through aluminum, wood, and plastics, while the metal index provides convenient organization for the 13-piece set.

Norseman 22893 Drill Bit Set

When it comes to tough materials like hardened steel and sheet metal, these drill bits more than hold their own. Coming in at just over 3 pounds, the set's got serious heft behind those 29 bits. The self-centering design with those helpful 3-flats on the shank means less wobble and more precise drilling.

Elite Titanium Drill Bit Set

Crafted from premium high-speed steel with a durable titanium coating, each drill bit undergoes rigorous heat treatment and engineering to deliver superior strength for the toughest materials. The secure 3-flat shank design prevents slips and ensures precise hole placement, while the optimized 135° split point reduces pressure and increases drilling efficiency. The collection, featuring eight specialized bits, comes complete with a metal carrying case that doubles as a handy transport and storage solution for your drilling tasks.

Drill America DMOD17/64 Solid Carbide Drill Bit

These solid carbide drill bits excel at piercing through tough materials like hardened steel and cast iron. The 17/64" bit, which extends 3.5 inches, features a straight shank that works with various tool systems. The twist design keeps the bit cool and tidy by flinging chips outward as it cuts.

Jefe Hex 115 Pcs Cobalt Drill Bit Set

Every engineer and hobbyist will love this comprehensive set of 115 drill bits, featuring high-speed steel with a robust 5% cobalt content. The included twist drill bits cut through even the toughest materials like stainless steel and titanium while maintaining their sharpness thanks to the 135-degree split point design. The clever organization system keeps your bits tidy in one sleek iron case, making it a practical addition to any workshop or garage toolbox.

Industrial Carbide Drill Bits

These solid carbide drill bits come in 12 precision sizes ranging from 1mm to 6.5mm, making them ideal for drilling through materials like aluminum, cast iron, copper, and steel. Coming pre-packaged in their spiral-flute design with 14mm to 33mm flute lengths, these Chinese-made bits provide reliable performance for both professional and DIY projects.

Grizzly T31985 13-Piece HSS Drill Bit Set

This 13-piece drill bit set handles tough jobs with its oversized 6-inch HSS bits, featuring step-shank designs that fit 1/2-inch chucks. The precision-tapered bits range from 17/32-inch to 1-inch diameters, making them perfect for punching through metal and other hard materials where standard bits fall short.

Grizzly Pro T33687 M2 Drill Bit Set

These M2 HSS drill bits combine high hardness with wear resistance for extended life between sharpenings. The titanium nitride coating not only boosts durability but also maintains cutting performance at elevated temperatures. The round shank design ensures secure bit positioning in the drill chuck, crucial for maintaining precision during heavy drilling.

Drill Hog USA 1/2" Drill Bit Set

Made from ultra-durable HI-Molybdenum M7 steel, these 6-pack drill bits feature a 135-degree split point and tri-flat shank design for consistent depth control. The bits effortlessly pierce through hardened materials like stainless steel, truck frames, and grade 8 bolts, while the included lifetime guarantee adds peace of mind to every project.

Cobalt Drill Bit Set

Made from high-speed steel M35 with 5% cobalt content, these 1/4-inch drill bits deliver lasting performance when tackling tough materials like stainless steel and cast iron. The 135-degree split point with a round straight shank keeps the bit centered during drilling, while the fully ground twist design efficiently removes chips and reduces friction. Each set includes 10 precision-ground drill bits measuring 2-3/4 inches long, packed in a handy plastic case for organized storage.

COMOWARE Cobalt Drill Bit Set

The 15-piece cobalt drill bit set combines 5% cobalt high-speed steel construction with a 135-degree split point design, making these jobber-length bits exceptionally capable for drilling through hardened metals like stainless steel and cast iron – as well as woodworking applications. Each bit features a durable round shank that fits standard drill chucks, while the 2-spiral flute design optimizes chip evacuation during use. The set includes multiple sizes from 1/16 to 3/8 inch, all housed in a protective plastic case for organized storage and transport.

Behappy 29pc High Speed Steel Carbide Drill Bit Set

This professional-grade drill bit set combines high-speed steel construction with precision engineering for versatile cutting performance in everything from metal and plastic to wood and hardened steel. The split-point design and spiral flutes work together to reduce friction and clear debris, maintaining consistent drill speed during even the toughest cuts. Each set comes complete with a portable metal case featuring a hanging mechanism for convenient storage and access.

HIDOTOL Cobalt Drill Bit Set

The high-speed M35 cobalt steel construction of these drill bits provides exceptional durability when working with tough materials like stainless steel and cast iron. Each bit features a precision 135° split point and round straight shank design that helps maintain alignment and prevent wandering during drilling. The fully ground spiral flutes efficiently remove debris and reduce friction, resulting in cooler operation and fewer tool changes.

18 Piece Cobalt Drill Bit Set

These drill bits pack serious power thanks to their cobalt-enhanced HSS core, making them perfect for cracking through tough metals like stainless steel and cast iron. The 135-degree split point keeps them from wandering, while the precision-ground spiral flutes blast out chips faster than you can say "don't get bit by a rabid squirrel. " Safety first: keep your drill steady and use cool lubricants for deep holes – trust us, you don't want these babies breaking off inside your project.

NordWolf 14-Piece M35 Drill Bit Set

These cobalt steel drill bits deliver exceptional durability for tough materials like stainless steel and cast iron. The precision-ground 135° split-point design ensures smooth, accurate drilling even through challenging metals and hardened materials. The set's comprehensive collection of SAE sizes covers everything from fine 1/16" holes to 3/8" diameters, all packed neatly in a labeled plastic case with a handy hanging clip.

COMOWARE Cobalt Drill Bit Set

These drill bits feature 5% Cobalt in M35 HSS, making them highly resistant to heat and wear. The 135° split point and spiral flutes prevent bit wandering and clear chips efficiently. Whether you're drilling through stainless steel, cast iron, titanium, or just regular old wood, these bits get the job done with their impressive durability. The included holder keeps them all organized and easy to find, with 29 fractional sizes, 26 letters, and 60 numbers to choose from.

MACXCOIP Cobalt Drill Bit Set

This comprehensive 29-piece drill bit set combines M35 cobalt and high-speed steel construction for versatile metalworking, featuring 135-degree spear points and spiral flutes optimized for swift cutting through stainless steel, cast iron, and other materials. The precision-tipped bits reduce wobble and improve chip clearance, while included holders with size indexes simplify organization and selection. Built for durability, these Chinese-made bits offer excellent value for both professional and serious hobbyist users.

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These 12 HSS drill bits combine a durable M2 steel core with titanium-coated flute walls for cleaner holes and extended lifespan. The 5/16" bits feature a 135-degree angle and 3-flat shank design, meeting ANSI specifications for precise metalworking. The black and gold coating helps prevent rust and corrosion in common materials like mild steel, copper, and aluminum.

Metric M42 Cobalt Drill Bits

These 13 precision drill bits combine exceptional heat resistance with remarkable durability, thanks to their premium cobalt construction. The three-step cutting edge reduces drilling pressure and prevents wandering, while their 135-degree split points ensure clean, accurate holes every time. The set includes bits ranging from 1.5mm to 6.5mm, making them versatile for both metal and plastic applications.

DeWalt 17pc Hex Shank Drill Bit Set

These DEWALT drill bits combine premium High Speed Steel construction with a durable tapered core design for consistent performance in tough materials like metal, wood, and PVC. The black and gold finish isn't just for show—it prevents rust and helps the bits last longer in your toolbox. With a reliable 1/4" hex shank that works great with most power drills and impact drivers, this 17-piece set gives you plenty of options for every drilling job.

STROTON 6% Cobalt Drill Bits Set

Made from premium 6% cobalt steel with 66-69 HRC hardness, these drill bits are built to last far longer than ordinary bits, resisting heat and wear while maintaining their sharpness. Each set includes two 3/8" diameter bits with 135-degree cutting angles and three-flat shank design for secure bit retention in your drill. The tough cobalt formulation lets you cut through stainless steel, iron plate, aluminum, and a variety of other materials, producing clean cuts that slice through metal instead of grinding it.

COMOWARE Titanium Twist Drill Bit Set

This high-speed steel drill bit set gives you 230 pieces of precision drilling power, from delicate 3/64" bits to sturdy 1/2" drillers. The titanium-coated, split-point bits slice through wood, metal, and plastic like hot knives in butter, while the straight-shank design keeps them steady in your drill. Each bit's round profile and dual-flute design shoves debris out of the way, making short work of even tough jobs like drilling through hardened steel.

Kobalt 21-Piece Titanium Drill Bit Set

This Kobalt drill bit set offers a mix of convenient features and troubled performance. The titanium coating increases speed and extends tool life, while the split-point design helps with initial penetration. However, users report frequent breakage, particularly with the smaller bits, and issues with the quick-change adapter. The set includes both metal and wood drill bits with a 1/4-inch hex shank, featuring a 135-degree split-point design for better start-cutting.

Mastercraft 230-Pc Titanium-Coated Drill Bit Set

The titanium-coated high-speed steel bits in this comprehensive 230-piece kit offer exceptional durability, lasting six times longer than conventional bits. The bits feature size markings on both the storage case and each individual tray, making it simple to find the right tool for the job.

Cobalt Drill Bit Set

The 13 cobalt drill bits in this set feature a durable plastic storage case and a 135-degree cutting angle, making them perfect for drilling into metals like stainless steel and cast iron. The titanium finish adds protection and extends the life of the bits. Each bit is carefully organized in a protective case to keep them sharp and ready for your next project.

STROTON Cobalt Drill Bit Set

Made from premium cobalt with a split-point tip design, these drill bits require less starting force and reduce walking across the material. The M35 grade holds up better than standard high-speed steel, especially when working with stainless steel and hard metals like cast iron and dense plastics. The professional-grade bits maintain their sharpness and efficiency through repeated use on both soft and hard materials.

Norseman 58660 Drill Set

This American-made drill set combines exceptional durability with precision engineering, featuring special Hi-Molybdenum tool steel and gold oxide coating for superior performance. The 135-degree split-point design ensures accurate centering and fast penetration, while the precision-ground geometry provides ultimate accuracy for even the most challenging jobs.

Drill America D/A15J-CO-SET M42 Cobalt Drill Bit Set

This American-made drill bit set brings serious firepower to your toolbox with its 15-piece collection of cobalt steel bits, perfect for cutting through the toughest metals like stainless steel and titanium. Each bit features a precise 1/32-inch step-down design from 1/16 to 1/2 inch, while the 135-degree split-point makes drilling a breeze. The gold-finished, right-hand cutting tools are built to last, giving you up to 30% faster speeds than conventional high-speed steel bits.

Cobalt Steel Twist Drill Bits

When it comes to drilling through tough metal, these Migiwata bits are the real deal. Made from that special M35 steel blend with just the right amount of cobalt to resist heat and stay sharp, they cut through hardened stainless steel and cast iron like a dream—and they won't cost you an arm and a leg in the long run. The 135-degree point means less strain on your drill and cooler operation, making these exactly what you need for serious metalworking projects.

HIDOTOL Cobalt Drill Bit Set

These premium drill bits feature high-speed steel M35 with 5% cobalt content, delivering exceptional durability when cutting through tough materials like stainless steel and cast iron. The 135° split point and self-centering design ensure precise drilling without wandering, while the fully ground spiral flute efficiently evacuates particles to maintain cool operation. The set includes 29 jobber-length bits spanning from 1/16" to 1/2" in 1/64" increments, providing a versatile solution for both soft and hardened materials.

MACXCOIP 115-Piece Cobalt Drill Bit Set

This comprehensive drill bit set combines precision with versatility, featuring 115 pieces including fractional, letter, and numbered sizes for every drilling challenge. The M35 high-speed steel bits excel in tough materials like stainless steel and cast iron while remaining surprisingly nimble for wood and plastic. The set's thoughtful design includes indexed holders and a 135-degree point for consistent, efficient cutting.

17PCS Cobalt Drill Bit Set

This 17-piece drill bit set handles everything from thin metal to plastic with its premium cobalt steel construction. The 66-69 HRC hardness gives these bits significantly longer life than standard drill bits, even when cutting through tough materials like stainless steel and cast iron. The split-point design and 135-degree flutes help prevent bit wander and create cleaner holes.

135° Titanium Twist Drill Bit Set

This comprehensive set of drill bits delivers impressive performance with its precision cutting edges and durable construction. Each bit features a 135° tip design that creates clean, accurate holes while the high-speed steel composition ensures longevity. The storage box keeps the bits organized and protected, making it a practical choice for both professionals and hobbyists who work with wood, cast iron, and aluminum.

EFFICERE Best Choice 8-Piece 1/2" Shank Drill Bit Set

Crafted from premium cobalt high-speed steel, these 8-piece drill bits form a versatile set for both professional and DIY use. The titanium-black nitride coating not only adds a stylish finish but also significantly improves durability and lubrication, particularly noticeable when working with harder materials like steel and copper. The universal 1/2" tri-flatted shank design ensures secure attachment to any 3-jaw power drill chuck, while the 135-degree split points facilitate smooth start-up and prevent wander during drilling.

Viking Drill Bit Set

Made for serious woodworkers and craftspeople, these premium drill bits pack a hefty 14-piece collection into one durable package. The special Hi-Molybdenum steel and precise manufacturing process mean these bits can handle anything from fine woodworking to metal drilling - and they perform exceptionally well, leaving clean holes with minimal tear-out. The USA-made tools come with a lifetime warranty, backed by Viking's reputation for quality that's earned through decades of crafting cutting-edge tools.

Premium M42 Cobalt Drill Bits Set

These premium 8% cobalt drill bits deliver exceptional performance when working with stainless steel and other hard metals. The 135-degree split-point design reduces drilling effort and prevents the bit from wandering, while the M42 steel composition provides superior heat resistance and long-term durability. With a set of 19 bits ranging from 1mm to 10mm, you'll have the right size for any job, from delicate 1mm holes to larger 10mm openings.

Norseman SP-115 Drill Bit Set

These USA-made drill bits combine tough Hi-Molybdenum steel with gold-surface treatment for lasting performance, particularly in stainless and other hard metals where regular bits struggle. The precision 135° split point makes quick work of starting holes without a center punch, and the heat-treated bits maintain their sharpness through tough drilling jobs.

Buyer's Guide

Drill bits for hardened steel require specific characteristics to penetrate and machine through hardened materials effectively. These specialized tools demand careful consideration of material composition, bit geometry, and manufacturing quality to achieve successful results.

Material Composition

The drill bit's material must match the hardness of the steel being drilled. Common choices include tungsten carbide-tipped bits for high-strength applications and high-speed steel (HSS) for more general use. Each material type has specific hardness ratings and heat resistance capabilities that affect drilling performance and tool longevity.

Geometry and Design

Optimal geometry includes a double-angle design with a primary and secondary cutting edge. The rake angle affects chip removal, while the clearance angle impacts chip evacuation. Additionally, the flute design should maximize chip flow while maintaining structural integrity during operation.

Cutting Characteristics

Hardened steel drilling requires controlled feed rates and appropriate speeds. Short bursts of drilling with frequent cooling and chip removal are more effective than continuous operation. Understanding the specific cutting requirements of the material ensures optimal tool performance and extended bit lifespan.

Manufacturing Quality

High-quality drill bits maintain precise angles and consistent surface finishes during manufacture. This attention to detail prevents premature wear and ensures accurate hole diameters. Additionally, proper coating treatments can enhance lubricity and prevent material buildup on the cutting edges.

FAQ

What is the difference between HSS and tungsten carbide drill bits?

HSS (High Speed Steel) drill bits are more commonly used for drilling hardened steel due to their flexibility and heat resistance. They maintain their sharpness well during drilling but may not be as durable as tungsten carbide bits for extremely tough materials.

Tungsten carbide-coated bits are highly resistant to wear and last much longer when drilling hardened steel. While more expensive, they deliver superior performance and faster drilling times compared to HSS bits.

How deep can standard drill bits penetrate hardened steel?

Standard drill bits typically achieve depths of 2-3 times their diameter when drilling hardened steel. For example, a 1/4" bit may penetrate 1-1.5" into steel, while a 5/8" bit can drill 2-2.5" deep.

Bit length and quality impact penetration depth. Longer or premium bits generally drill deeper, while standard bits reach their maximum depth at 2-3 times their diameter.

What causes drill bit breakage when drilling hardened steel?

Excessive heat, lack of lubrication, and improper bit selection are primary causes of breakage. Standard HSS bits can seize and break when drilling very hard steel at high speeds.

Using the correct bit type (tungsten carbide or HSS specifically designed for hardened steel), maintaining appropriate feed rates, and ensuring proper cooling significantly reduce breakage risk.

How long do quality drill bits last when used on hardened steel?

High-quality HSS bits last 2-3 times longer than standard bits, typically surviving 20-40 holes per bit in hardened steel, depending on material hardness and drilling conditions.

Tungsten carbide-coated bits, while more expensive, last 5-10 times longer than HSS bits, surviving 100-200 holes before replacement is needed.

What are the most common sizes for hardened steel drill bits?

Standard drill bit sizes range from 1/32" to 1" in diameter, with common sizes being 1/8", 5/16", and 3/8". These cover most applications for drilling hardened steel.

Specialty sizes beyond this range are available for specific applications, but the most frequently used sizes are within the 1/32" to 1" range.

How should drill bits be maintained after use in hardened steel?

Aftersharpening with a grinding wheel or diamond file restores bit geometry and extends life. Bit surfaces should be free of black residue, which indicates excessive heat buildup.

Regular cleaning with a steel brush removes carbon deposits and prevents corrosion. Proper storage in a dry place protects bits between uses and maintains their integrity.

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