What are the models of stainless steel drill bit?

Stainless steel is renowned for its corrosion resistance, strength, and durability, but these properties also make it one of the most challenging materials to drill. Its high hardness, low thermal conductivity, and tendency to work-harden require specialized drill bits designed to withstand extreme friction and heat. Over the years, manufacturers have developed various models of stainless steel drill bits, each tailored to specific applications, stainless steel grades, and drilling conditions. This guide explores the primary models, categorized by material, coating, and application, along with detailed insights into leading brands and their flagship products.

1. High-Speed Steel (HSS) Drill Bits for Stainless Steel

High-Speed Steel (HSS) is a common base material for drill bits, valued for its balance of toughness and heat resistance. While standard HSS bits are suitable for mild steels, stainless steel demands modified HSS formulations. These bits are often heat-treated to enhance hardness (typically 62-65 HRC) and feature optimized flute designs to improve chip evacuation—critical for preventing work-hardening in stainless steel.

Bosch HSS-R Series

Bosch, a leader in power tool accessories, offers the HSS-R series as an entry-level option for stainless steel drilling. The model 2608585249 is a standout, designed for general-purpose stainless steel work, including grades like 304 and 430. Constructed from high-speed steel with a 0.8% carbon content and alloying elements like chromium (4%), vanadium (1%), and molybdenum (5%), this bit achieves a hardness of 63 HRC, striking a balance between sharpness and durability. Its flute design features a 30° helix angle, which promotes steady chip flow to reduce heat buildup—a common issue when drilling stainless steel. The shank is a standard cylindrical type (DIN 338), compatible with most hand drills and bench drills, with diameters ranging from 1mm to 13mm. The bit undergoes a black oxide coating process, which reduces friction and enhances wear resistance, though it is less robust than titanium-based coatings. Users report reliable performance for occasional drilling tasks, though it may require frequent re-sharpening for heavy use on thick stainless steel sheets.

DeWalt HSS General Purpose Drill Bits

DeWalt’s DW1177 is another HSS model tailored for light to moderate stainless steel drilling. Built with a precision-ground point and cutting edges, this bit ensures accurate positioning, minimizing the risk of slipping—a common problem when starting holes in smooth stainless steel surfaces. The HSS formulation here includes 0.7% carbon, 4% chromium, and 2% molybdenum, with a hardness of 62 HRC. Its flutes are designed with a parabolic shape, which increases chip evacuation efficiency compared to straight flutes, reducing heat and extending bit life. The shank is a 1/4-inch hex design, compatible with impact drivers, making it versatile for both hand drills and power tools. Available in diameters from 1/16-inch to 1/2-inch, the DW1177 is recommended for 304 and 430 stainless steel, though DeWalt advises against prolonged use on harder grades like 316. The bit’s surface features a bright finish, which lacks the friction-reducing benefits of coated bits but allows for easier inspection of wear on the cutting edges.

2. HSS-Co (Cobalt) Drill Bits: Enhanced for Harder Stainless Steels

HSS-Co (High-Speed Steel with Cobalt) drill bits are the gold standard for stainless steel drilling, especially for harder grades like 316, duplex, or precipitation-hardening stainless steels. Cobalt (typically 5-10% by weight) increases the alloy’s red hardness—its ability to retain hardness at high temperatures—making these bits resistant to the extreme heat generated when drilling stainless steel.

Irwin Industrial Tools Cobalt M-42 Series

Irwin’s 3018002 is a flagship model in the Cobalt M-42 series, featuring 8% cobalt content for superior performance. M-42 steel, an alloy with 1.1% carbon, 4% chromium, 1.8% vanadium, and 8% cobalt, achieves a hardness of 65 HRC, making it ideal for drilling 316 stainless steel and even cast stainless alloys. The bit’s cutting edges are precision-ground with a 135° split point, which self-centers to prevent walking and reduces the need for pre-drilling pilot holes—a significant time-saver. Its flutes have a 38° helix angle, optimized for fast chip removal, and are polished to minimize friction. The 3018002 comes with a titanium carbonitride (TiCN) coating, which combines the hardness of titanium carbide (TiC) with the lubricity of titanium nitride (TiN), reducing heat and wear. Available in diameters from 1/16-inch to 1/2-inch, with a 1/4-inch hex shank for compatibility with impact drivers, this model is praised for its longevity—users report drilling over 100 holes in 316 stainless steel (1/4-inch thick) before showing signs of wear. Irwin also offers the 3018006 variant, a larger set with diameters up to 3/4-inch, designed for heavy-duty applications.

Milwaukee Red Helix Cobalt Drill Bits

Milwaukee’s 48-89-2330 is part of their Red Helix series, engineered for aggressive yet controlled drilling in stainless steel. This model features 5% cobalt content (M-35 steel), with a composition of 0.8% carbon, 4% chromium, 2% molybdenum, and 5% cobalt, achieving a hardness of 64 HRC. The “Red Helix” flute design is the key innovation here: a variable helix angle (starting at 25° near the shank and increasing to 35° at the tip) that enhances chip evacuation by creating a spiral path that clears debris more efficiently than fixed-angle flutes. This reduces clogging, a common issue when drilling stainless steel, which can cause overheating and bit failure. The cutting edges are reinforced with a proprietary “Pilot Point” design, ensuring precise starts even on polished stainless steel surfaces. The 48-89-2330 is coated with titanium aluminum nitride (AlTiN), a high-performance coating that withstands temperatures up to 1,100°C (2,012°F)—far higher than the heat generated during stainless steel drilling. Available in diameters from 1/16-inch to 1/2-inch, with a cylindrical shank, this bit is recommended for both hand drills and CNC machines. Milwaukee claims a 30% longer lifespan than standard HSS-Co bits when drilling 304 stainless steel.

Makita B-65399 Cobalt Drill Bit Set

Makita’s B-65399 is a 29-piece set of HSS-Co drill bits, designed for professional use on stainless steel and other hard metals. Each bit in the set is made from M-42 steel with 8% cobalt, ensuring high red hardness and wear resistance. The bits feature a 135° split point for self-centering and reduced thrust, which is crucial for preventing bit deflection when drilling thick stainless steel plates. The flutes are ground to a parabolic shape, which increases the volume of chip removal, reducing heat buildup. A black oxide coating is applied to minimize friction and corrosion, though it is less durable than TiAlN coatings. The set includes diameters from 1/16-inch to 1/2-inch, with a 3/8-inch reduced shank for larger bits, allowing them to fit in drills with 3/8-inch chucks. Makita’s precision grinding process ensures consistent cutting edges across all bits in the set, making them reliable for batch production tasks. Users note that the B-65399 performs exceptionally well on duplex stainless steel (e.g., 2205), a material known for its high strength and difficulty to machine.

3. Tungsten Carbide Drill Bits: For Extreme Hardness and Precision

Tungsten carbide drill bits are the hardest option for stainless steel drilling, made from a composite of tungsten carbide particles (90-95%) bonded with cobalt (5-10%). They offer superior wear resistance and hardness (up to 90 HRC) compared to HSS-Co bits, making them ideal for high-volume production, hard stainless steel grades (e.g., 440C), or drilling through stainless steel with abrasive inclusions.

Sandvik Coromant R840 Carbide Drill Bits

Sandvik Coromant, a leader in cutting tools, offers the R840 series, a solid carbide drill bit designed for precision stainless steel drilling. The R840-0600-Q3-11 is a popular model, with a diameter of 6mm, optimized for 316L and duplex stainless steels. The carbide grade used is GC4335, a micrograin carbide with submicron particles (0.8-1.2μm) that enhance toughness and wear resistance. The bit features a 140° point angle with a reinforced cutting edge, reducing chipping when encountering hard spots in the material. Its flute design incorporates a high helix angle (38°) and polished surfaces to ensure smooth chip flow, critical for preventing chip jamming in deep holes. The R840 is coated with CVD (Chemical Vapor Deposition) TiAlN, which provides a hard, heat-resistant layer that extends tool life. The shank is a cylindrical type with a precision ground finish, ensuring concentricity in high-speed CNC machines. Sandvik recommends using this bit at speeds between 20-40 m/min (65-130 ft/min) with coolant to maximize performance, and it is capable of drilling holes up to 5× diameter depth (30mm for the 6mm model). The R840 is pricier than HSS-Co bits but offers up to 5 times longer life in high-volume applications.

Kennametal KSEM Carbide Drill Bits

Kennametal’s KSEM series is engineered for high-performance drilling in stainless steel, with the KSEM0750A06 being a standout model for 7.5mm diameter holes. Constructed from KCPM15 carbide, a grade with 94% tungsten carbide and 6% cobalt binder, this bit balances hardness (91 HRC) and toughness, making it suitable for interrupted cuts and variable material thicknesses. The cutting geometry features a split point with a 130° angle, which reduces axial force and improves centering, while the flutes are designed with a variable helix to optimize chip evacuation in both shallow and deep holes (up to 8× diameter). The KSEM0750A06 is coated with PVD (Physical Vapor Deposition) AlTiN, which has a lower friction coefficient than CVD coatings, reducing heat buildup during high-speed drilling. Kennametal’s “Edge Intelligence” technology ensures consistent edge preparation across all bits, minimizing variability in performance. This model is compatible with CNC machines and is recommended for drilling 304, 316, and 410 stainless steels, with a suggested feed rate of 0.1-0.15mm/rev. Users highlight its ability to maintain precision even after hundreds of holes, making it a favorite in industrial manufacturing.

Guhring 5000 Carbide Drill Bits

Guhring’s 5000 series is a versatile carbide drill bit designed for stainless steel and other difficult-to-machine materials. The 5000-0500 (5mm diameter) features a micrograin carbide substrate with a cobalt binder, ensuring high hardness and resistance to thermal shock. Its cutting edge is honed to a radius of 0.02mm, reducing the risk of chipping when drilling through work-hardened layers in stainless steel. The flute design incorporates a “Super-Flow” geometry, which increases chip evacuation efficiency by 20% compared to standard flutes, preventing clogging and overheating. The 5000-0500 is coated with TiSiN (Titanium Silicon Nitride), a coating that offers higher oxidation resistance than TiAlN, making it suitable for dry drilling applications where coolant is unavailable. The shank is a cylindrical type with a coolant hole (through-coolant design), allowing for direct coolant delivery to the cutting edge—critical for reducing heat in stainless steel drilling. Guhring recommends this bit for speeds up to 50 m/min (164 ft/min) and feeds of 0.12mm/rev, with excellent performance reported on 430 and 440C stainless steels.

4. Coated Stainless Steel Drill Bits by Coating Type

Coatings play a pivotal role in extending drill bit life by reducing friction, dissipating heat, and enhancing wear resistance. Different coatings are optimized for specific conditions, from high-speed drilling to dry environments.

TiN (Titanium Nitride) Coated Bits

TiN coatings, known for their golden color, are a popular choice for general stainless steel drilling. They reduce friction and increase surface hardness, making them suitable for moderate-duty applications.

Bosch Professional TiN-Coated HSS-Co Bits

Bosch’s 2608585575 is a TiN-coated HSS-Co drill bit with 5% cobalt content, designed for 304 and 430 stainless steels. The TiN coating is applied via PVD, creating a 3-5μm thick layer with a hardness of 2,000 HV (Vickers), which reduces friction between the bit and the workpiece. This lowers heat generation and prevents material from adhering to the cutting edges—a common issue with stainless steel’s high ductility. The bit features a 118° point angle, a standard design for general-purpose drilling, and a cylindrical shank. Diameters range from 3mm to 10mm, with a 30° helix angle for efficient chip removal. Users note that while the TiN coating wears faster than AlTiN in high-heat applications, it provides excellent value for occasional use, with the 2608585575 lasting 2-3 times longer than uncoated HSS bits.

TiCN (Titanium Carbonitride) Coated Bits

TiCN coatings, darker in color than TiN, offer higher hardness (2,800 HV) and better wear resistance, making them ideal for high-speed drilling in stainless steel.

Irwin Turbo Max TiCN-Coated Bits

Irwin’s 3018004 is part of their Turbo Max line, featuring a TiCN coating on an HSS-Co (8% cobalt) base. The coating’s low friction coefficient (0.4 compared to TiN’s 0.6) reduces heat buildup, allowing for higher drilling speeds—up to 1,500 RPM for 1/4-inch bits in 304 stainless steel. The 3018004 has a 135° split point for self-centering and a parabolic flute design that enhances chip flow. Available in diameters from 1/8-inch to 3/8-inch, with a hex shank, this bit is compatible with impact drivers, making it versatile for on-site and workshop use. Users report that the TiCN coating retains its integrity even after prolonged use, with minimal edge wear, making it a reliable choice for medium-volume tasks.

AlTiN (Aluminum Titanium Nitride) Coated Bits

AlTiN coatings are the most heat-resistant option, withstanding temperatures up to 1,100°C, making them perfect for high-speed, heavy-duty stainless steel drilling.

Milwaukee Shockwave AlTiN-Coated Bits

Milwaukee’s 48-89-2960 is a Shockwave Impact Duty drill bit with an AlTiN coating, designed for use with impact drivers and drills on stainless steel. The base material is HSS-Co with 5% cobalt, and the AlTiN coating (5μm thick) provides a hardness of 3,000 HV, ensuring resistance to abrasion and heat. The bit features a “Shockwave” flute design, which is reinforced to withstand the high torque of impact drivers, preventing breakage—a common issue with standard bits in impact applications. The 135° split point ensures accurate starts, while the variable helix angle (25° to 35°) optimizes chip evacuation. Available in diameters from 1/16-inch to 1/2-inch, this model is recommended for 316 stainless steel and is praised for its durability, with users reporting consistent performance even after 50+ holes in 1/4-inch thick material.

ZrN (Zirconium Nitride) Coated Bits

ZrN coatings, silver in color, offer good lubricity and corrosion resistance, making them suitable for wet drilling applications or in corrosive environments.

Dormer Pramet ZrN-Coated HSS Bits

Dormer Pramet’s A116-ZrN is an HSS drill bit with a ZrN coating, designed for stainless steel drilling in marine or chemical environments where corrosion resistance is critical. The base material is HSS with added chromium for corrosion resistance, and the ZrN coating (4μm thick) reduces friction and prevents rust on the bit itself. The 118° point angle and straight flutes make it suitable for shallow holes in 304 and 316L stainless steel, while the cylindrical shank fits standard chucks. The ZrN coating also provides a low coefficient of friction (0.35), reducing heat and extending bit life in wet conditions (e.g., with water-based coolants).

5. Application-Specific Stainless Steel Drill Bits

Beyond general-purpose models, manufacturers offer drill bits tailored to specific applications, such as deep-hole drilling, step drilling, or drilling thin stainless steel sheets.

Deep-Hole Drill Bits

Deep-hole drilling in stainless steel requires bits with enhanced chip evacuation and rigidity to prevent deflection.

Walter Titex X·treme D4000 Deep-Hole Bits

Walter Titex’s X·treme D4000 is a carbide deep-hole drill bit capable of drilling holes up to 10× diameter depth in stainless steel. The model D4000-1000-100 (10mm diameter) features a solid carbide construction with a GC1030 grade, optimized for toughness in deep cuts. Its flute design includes a large chip flute volume and a polished surface to ensure debris is cleared efficiently, even at depth. The cutting edge is reinforced with a “Stabilizer” feature, a small guide pad near the tip that reduces vibration and ensures straight holes. The bit is coated with AlTiN for heat resistance and has through-coolant holes to deliver coolant directly to the cutting zone. Walter recommends speeds of 30-40 m/min and feeds of 0.1-0.12mm/rev for 316 stainless steel, with excellent results reported in automotive and aerospace applications where deep, precise holes are required.

Step Drill Bits

Step drill bits are ideal for drilling multiple hole sizes with a single bit, making them popular for thin stainless steel sheets (0.5-3mm thick).

Ridgid Step Drill Bit for Stainless Steel

Ridgid’s 37408 is a 3/8-inch to 1/2-inch step drill bit designed for stainless steel. Constructed from HSS-Co with 5% cobalt, it features a TiN coating for reduced friction and a 135° point angle for clean starts. The step design includes 8 steps, allowing for hole diameters from 3/8-inch to 1/2-inch in 1/32-inch increments, eliminating the need for multiple bits. The flutes are short and wide to quickly evacuate chips from thin material, preventing jamming. The hex shank fits impact drivers, and the bit is reinforced at the shank-tip junction to prevent bending when drilling thin, flexible stainless steel sheets. Users note that the 37408 produces burr-free holes in 304 stainless steel, a key advantage for applications where post-drilling deburring is time-consuming.

Self-Centering Drill Bits

Self-centering bits are designed to prevent walking on smooth stainless steel surfaces, ensuring accurate hole placement without pre-drilling.

Vermont American Self-Centering Drill Bits

Vermont American’s 16518 is a self-centering drill bit with a 1/4-inch diameter, ideal for stainless steel hardware installation (e.g., bolts, screws). The bit features a spring-loaded center punch that creates a small indentation before the cutting edges engage, ensuring precise positioning. The base material is HSS-Co with 5% cobalt, and the cutting edges are ground to a 90° angle to create flat-bottomed holes, which are ideal for countersinking screws. The flute design is optimized for chip removal in thin to medium stainless steel (1-5mm thick), and the cylindrical shank fits standard drills. This model is popular among DIY enthusiasts and professionals for its ease of use and accuracy on polished stainless steel surfaces.

6. Brand-Specific Innovations in Stainless Steel Drill Bits

Leading brands continuously innovate to improve performance, with unique technologies that set their models apart.

Bosch X-Line Technology

Bosch’s X-Line series, including the 2608585700, incorporates “X-Line” technology—a proprietary heat treatment process that increases the bit’s toughness by 15% compared to standard HSS-Co bits. This process involves double tempering the steel, creating a uniform microstructure that resists chipping during heavy use. The 2608585700 also features a “Progressive Flute” design, where the flute depth increases gradually from the tip to the shank, improving chip evacuation in deep holes. These innovations make it a top choice for professionals drilling thick stainless steel plates (6-10mm).

DeWalt Pilot Point Design

DeWalt’s Pilot Point bits, such as the DW1354, feature a sharp, conical tip that penetrates stainless steel quickly, reducing the force required to start drilling. This design minimizes work-hardening around the hole, which can make drilling more difficult. The DW1354 is made from HSS-Co with 5% cobalt and has a TiAlN coating, with diameters ranging from 1/8-inch to 1/2-inch. Users report that the Pilot Point design reduces drill bit “wandering” by 70% compared to standard bits, making it ideal for precision applications.

Makita Ultra Coat Coating

Makita’s Ultra Coat, used in models like the D-74891, is a multi-layer PVD coating that combines TiN, TiCN, and AlTiN layers. This coating system provides a hardness of 3,200 HV and withstands temperatures up to 1,200°C, making it one of the most heat-resistant options on the market. The D-74891 is a carbide bit designed for high-speed CNC drilling, with a micrograin carbide substrate that ensures consistent performance in mass production.

Milwaukee Red Helix Flute Geometry

Milwaukee’s Red Helix design, featured in the 48-89-2330 and other models, uses a variable helix angle to create a spiral that actively pulls chips out of the hole, reducing heat and clogging. This geometry is particularly effective in stainless steel, where chips can be long and stringy, potentially jamming the flute. Testing shows that Red Helix bits reduce drilling time by 20% compared to fixed-helix bits in 316 stainless steel.

Conclusion

Stainless steel drill bits come in a wide range of models, each optimized for specific materials, applications, and tools. From entry-level HSS bits for occasional use to high-performance carbide bits for industrial production, the right model depends on factors like stainless steel grade, hole depth, drilling speed, and volume. Brands like Bosch, DeWalt, Irwin, Milwaukee, and Sandvik Coromant lead the market with innovations in materials, coatings, and flute designs, ensuring that professionals and DIY enthusiasts alike can find a drill bit tailored to their needs. By understanding the differences between HSS, HSS-Co, and carbide bits, as well as the benefits of various coatings, users can select the optimal model to achieve clean, precise holes in stainless steel while maximizing bit life and efficiency. Whether drilling thin sheets or deep holes in hard 316 stainless steel, the right drill bit model is essential for success in this challenging material.

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