10 Best Drill Bits For Drilling Stainless Steel in 2026

Bosch uses an 8% cobalt M42 alloy for these bits, which the manufacturer states delivers ten times the life of standard bits. This high-cobalt content and a surface-hardened tip are designed for high heat resistance when drilling tough materials like stainless steel and cast iron. The three-flat shank on bits 3/16 inch and larger provides a better grip in the chuck, which helps reduce slipping during demanding applications.

The set comes in a plastic case. For users who need a more compact set designed for impact drivers, the NordWolf M35 Cobalt Hex Shank set is one alternative with a hex shank. The Bosch CO21B offers a 21-piece assortment of jobber-length bits specified for drilling stainless steel, cast iron, titanium, light-gauge metal, and aluminum.

Its impact-driver rating means these bits are designed for the high-torque environment of a 1/4-inch hex impact driver, a key detail for users who primarily drive with that tool. The titanium nitride coating lasts 2.5 times longer than non-coated bits, providing extra wear resistance for materials like stainless steel. According to the specifications, the set is intended for drilling ferrous metal, wood, plastic, non-ferrous metal, cast iron, and stainless steel.

The trade-off is in specialization and range. You’re getting a focused set of 14 commonly used sizes up to 1/4 inch, not the expansive range of a 21-piece cobalt set like the Bosch CO21B. For a dedicated drill press or a cordless drill where you need a wider array of precise sizes for detailed work, a traditional cobalt set will be more versatile. But for the impact driver user, this Makita set nails the core requirement: durability under punishment.

With its TiAlN coating rated for temperatures up to 1472°F, this set is engineered to combat the heat that destroys drill bits when working stainless steel or hardened cast iron. That extreme heat resistance translates to a longer tool life compared to bits with standard coatings. Furthermore, the innovative three-flute geometry on most sizes improves chip ejection by about 40%, a design that keeps the bit running cooler and delivers superior hole roundness for a smoother finish. For regular metal drilling, these features combine to offer a durable and precise tool that resists the wear common in demanding shop environments.

The triple-flute design is recommended for standard depth of cut applications, not for deep, single-pass boring. While the set is comprehensive, the very smallest bits switch to a two-flute design. This is a sensible engineering choice for delicate work, but it means the full triple-flute performance isn’t available across the entire range. For the vast majority of stainless steel fabrication and repair, however, the Crosstar’s advanced heat management and its three-flat shank for maximum grip are hard to beat.

This set’s M42 8% cobalt construction and 135-degree split points are built for one thing: chewing through stainless steel and hard metals without constantly stopping to sharpen. The 19 pieces cover a solid metric range from 1mm to 10mm in half-millimeter increments, which is a dream for machinists or anyone working on European equipment. It’s the logical choice for a workshop that lives and breathes metric measurements and needs a durable, purpose-driven set for frequent metalwork. The bits are designed to cut long, curling chips instead of grinding, which reduces heat buildup and extends tool life on tough materials.

The set’s strictly metric sizing from 1mm to 10mm is focused for work with millimeter specifications, unlike some other cobalt sets that may include imperial sizes. Its jobber-length bits, with the longest at 13cm, are not designed for deep-pocket drilling applications. For drilling stainless steel and hard metals where metric sizes are required, the specialized cobalt formula and incremental sizing aim to provide consistent performance.

A hex shank locks securely into any power tool with a quick-change chuck, which prevents slippage when drilling. The M35 cobalt construction and titanium coating make the bits harder than typical HSS, improving heat and corrosion resistance for demanding metalwork. An aluminum storage case keeps the set organized and portable for a toolbox or jobsite.

This set is a specialist for creating or enlarging holes in sheet materials, not for deep drilling. For a single, deep hole in solid metal, a dedicated twist bit like those in the Bosch CO21B set is required. The step design allows one bit to produce multiple hole sizes in a smooth operation, working on materials like heavy metal, iron, aluminum, brass, plastic, and wood.

The Milwaukee 48-89-2338 set includes 29 cobalt drill bits, so you have a wide size range ready for extended metalworking. Its Amazon category lists it for metalworking and multipurpose drilling, which covers tasks from small pilot holes to larger openings in tough materials. The included case organizes all the pieces, making it a fit for a stationary workshop or a service vehicle with ample storage, rather than for occasional, single-hole use.

The trade-off for that completeness is bulk. The case is substantial, so it won’t tuck into a small portable tool bag like the compact NordWolf hex shank set. If your work involves climbing a ladder or squeezing into tight spaces, this full-sized kit will feel like overkill. For a stationary workshop or a mobile rig where comprehensive capability trumps portability, this Milwaukee set organizes your drilling needs into one heavy-duty package.

A 29-piece set with sizes running from 1/16 inch to 1/2 inch in 1/64-inch increments gives you a tool for nearly any hole size needed in stainless steel fabrication or repair. The 5% cobalt alloy is the key here, standing up to the heat and abrasion of hard metals without losing its edge prematurely. This makes it a logical choice for a workshop that needs a single, complete inch-set for drilling stainless steel, cast iron, and other tough materials. The heavy-duty web and split-point design mean you start cutting where you intend to, not where the bit decides to skate.

The comprehensive size selection requires a larger case, and the round shanks limit use to drill presses or standard keyed and keyless chucks. Compared to a hex-shank set like the NordWolf M35 Cobalt, these bits are not designed for quick-change chucks or impact drivers. This design suits users who need a full range of fractional-inch bits for a dedicated workshop setup.

A 1/4-inch hex shank makes this set a standout for anyone who frequently swaps bits in a quick-change chuck or impact driver. You save time fumbling with a keyless chuck, especially in tight spaces. The M35 cobalt composition and 135-degree split point tip are built for the hard stuff, stainless steel, cast iron, titanium, biting in cleanly without walking. For the mechanic or fabricator who needs a reliable, fast-swapping set for common small to medium-sized holes in tough materials, this NordWolf kit delivers the right foundation.

The NordWolf M35 Cobalt set covers a practical range of imperial sizes from 1/16 inch up to 1/4 inch, which handles most common drilling tasks in metal. For holes larger than a quarter-inch, you will need to look at a different set. The included sizes are laser-marked on the storage rail for quick identification, so you spend less time searching and more time drilling.

These bits are defined by their stubby length, measuring between 1.83 and 2.32 inches. That compact build is the whole point, granting access to hard-to-reach and tight spaces where a standard-length drill bit cannot fit. M35 cobalt steel provides durability for drilling stainless steel and hardened metals, while the 135-degree split point helps with self-centering to prevent the bit from walking off the mark.

The set includes five common imperial sizes, from 3/32 to 5/16 of an inch. This focused selection makes it a specialized tool for specific clearance problems rather than a primary, comprehensive drill bit set. When a hole is needed in a confined area, this is the set to reach for, but it is not intended to cover a wide range of drilling diameters.

A set of three M35 cobalt step bits with a TiAlN coating means you can tackle a range of hole sizes in sheet metal without swapping tools. The 1/4-inch hex shank design eliminates slipping in a drill chuck, so it fits securely in tools like impact drills and bench presses. This set suits anyone who regularly needs to enlarge, deburr, or chamfer clean holes in stainless steel under 1mm, aluminum, copper, or plastic up to 7/8 inches. It’s a focused kit for fabrication and metalworking tasks where a stepped hole is the goal.

These bits specialize in enlarging existing holes or working with thin sheet metal, but they aren’t for drilling pilot holes in thick stock. For that, you’d need a standard twist drill set. Compared to a 21-piece cobalt twist drill set like the Bosch CO21B, the SS SHOVAN set covers a narrower, more specific function. It’s a powerful specialist, not a generalist.