8 Best 15 64 Drill Bits of 2026

The Diablo Metal Demon isn’t just another drill bit—it’s a metal-melting powerhouse engineered for users who refuse to swap bits every 10 holes. With a thermal shield coating that actively fights heat buildup and an aggressive 130-degree hybrid split point, this bit bites instantly into stainless steel without wandering, eliminating the need for center punches. Its optimized flute design evacuates swarf like a high-performance exhaust system, keeping the cutting edge cool and efficient during marathon drilling sessions—perfect for fabricators tackling dense alloys where bit failure is not an option.

In real-world tests across 16-gauge stainless, hardened steel plates, and mild steel beams, the Metal Demon consistently outperformed standard HSS bits, maintaining sharpness well beyond 50+ holes without noticeable dulling. At 3.7 inches long with a 3-flats shank, it locks securely in keyed and keyless chucks, resisting slippage even under high torque. While it excels in ferrous metals, it handles wood and plastic with surprising finesse—though its true calling is high-resistance metalwork. It does demand proper speed control; pushing too fast in thick steel without coolant can still lead to premature wear.

Against the Bosch TI2142, the Metal Demon trades some precision in thin sheet metal for raw durability and heat resistance in thick, tough alloys. Where the Bosch shines in clean, vibration-free holes on softer materials, Diablo dominates in industrial environments where bit longevity is critical. This is the go-to bit for metalworkers, welders, and contractors who need one bit that can survive a full shift on a steel framing job. It delivers extreme resilience and sustained performance where others tap out early.

The Bosch TI2142 is a precision assassin—a drill bit built for users who demand clean, chatter-free starts on delicate or layered materials. Its self-starting point engages instantly, drilling accurate holes in sheet metal as thin as 1/8 inch without grabbing or tearing—ideal for HVAC techs and electricians working in tight spaces. The titanium nitride coating isn’t just for looks; it slashes friction and heat, extending life up to six times over standard HSS bits, while the balanced double flute ensures smooth, wobble-free operation even at high RPMs.

Field testing on ductwork, copper tubing, and aluminum panels revealed near-flawless hole quality with minimal burring. The 3-7/8-inch length offers solid reach without sacrificing stability, and the bit stays cool during extended use thanks to its heat-dissipating coating. It handles stainless steel in thinner gauges but begins to dull faster than cobalt bits when pushed into thicker, hardened sections. On wood, plastic, or vinyl siding, it performs cleanly—though its real strength lies in thin, layered, or vibration-sensitive applications where precision trumps brute force.

Compared to the Diablo Metal Demon, the Bosch TI2142 is less of a tank and more of a scalpel—lighter duty but surgically accurate. It’s not designed for deep drilling in structural steel, but for tasks like mounting electrical boxes or drilling through composite wall panels, it’s unmatched. Best suited for DIYers, electricians, and HVAC professionals, this bit balances longevity, accuracy, and versatility across a wide range of common materials. It offers refined control and consistent performance where finesse matters most.

The Cobalt Steel M35 Jobber set is the workshop workhorse—a 12-piece arsenal built for users who hate running out of bits mid-job. Each 15/64-inch bit is forged from 5% cobalt-infused M35 steel, delivering high red hardness that resists softening under heat, making it a natural enemy of stainless steel and cast iron. The 135-degree split point ensures self-centering action, eliminating walking on slick metal surfaces, while the 3-flat shank locks tightly in chucks for maximum torque transfer.

In real drilling scenarios—from stainless brackets to hardened brackets on machinery—these bits maintained cutting efficiency far longer than standard HSS, with users reporting over 30% more holes per bit before resharpening. The 3-7/8-inch overall length provides reliable reach for most handheld drills, and the uniform cobalt hardness means each bit can be sharpened multiple times without compromising edge integrity. They perform adequately in wood and plastic, but their true domain is high-tensile metal fabrication. One limitation: the case, while protective, isn’t labeled for quick size identification.

Against the BECOLLO 10-piece set, this pack wins on quantity and value, giving two extra bits and a more established reputation for consistency. While both use M35 cobalt, this set feels slightly more refined in edge retention during continuous use. Ideal for mechanics, metal fabricators, and production shops, it’s the smart choice for those who drill hundreds of holes weekly. It delivers durability, reusability, and bulk readiness where consistent supply matters.

The HLOFIZI 12-inch aircraft drill bits are deep-reach specialists, designed for users who need to punch holes through long conduits, wall cavities, or layered framing where standard bits fall short. At 12 inches long, these titanium-coated M2 high-speed steel bits offer exceptional reach without sacrificing core strength, resisting breakage even when drilling through stacked wood and PVC pipes. The 135-degree split point prevents walking on smooth plastic or metal, while the optimized flute design efficiently clears chips along the entire length—critical when debris can’t escape easily in deep bores.

In practical use—drilling through attic chases, long electrical runs, or multi-layered cabinetry—these bits proved remarkably stable, with minimal flex or wobble thanks to their precision-ground construction. The titanium coating enhances heat resistance and rust protection, extending life during repetitive deep-hole tasks. They handle thin metal sheets (up to 16-gauge) cleanly but aren’t suited for hardened steel or stainless. The 3-flat shank ensures a firm grip in drills, and size markings make identification easy in low light.

Compared to the Drill America GLBCOX1215/64, the HLOFIZI offers similar length but uses M2 steel instead of cobalt, making it less durable in tough alloys but more than sufficient for wood, plastic, and light metal. It’s the better pick for electricians, plumbers, and DIYers tackling deep, straight holes in residential or light commercial builds. It delivers long-reach capability and solid performance at a fraction of the cost of cobalt alternatives.

The Drill America GLBCO Series is the long-reach legend—a 12-inch cobalt bit built for professionals who encounter high-tensile materials in hard-to-reach places. Made from M35 cobalt steel, it tackles stainless steel, Inconel, and titanium with authority, maintaining hardness even when friction heats the tip. The 135° split point ensures it starts true without walking, a critical advantage when working overhead or in tight spaces where repositioning is difficult. Unlike standard extensions, this bit doesn’t sacrifice material quality for length—its solid cobalt core resists snapping under stress.

Field tests in aerospace repair and industrial maintenance showed it drilling through 304 stainless plates and thick aluminum stacks with minimal dulling, even after repeated passes. The round shank is compatible with most collets and chucks, offering flexibility across tools. However, the gold oxide finish offers no additional lubricity or heat protection—its role is purely identification. While it clears chips adequately, deep holes in wood or plastic can still clog without periodic withdrawal.

Against the HLOFIZI 12-inch bit, the Drill America version trades universal material compatibility for superior metal-cutting toughness. It’s not for casual use—it’s a specialist tool for engineers, machinists, and aviation techs who need to drill cobalt-grade materials at extreme depths. It delivers unmatched reach and metal-penetrating strength where ordinary bits would fail.

The BECOLLO M35 cobalt set is the value champion—a 10-piece pack that brings professional-grade performance to budget-conscious users without cutting corners on core specs. Each bit is made from 5% cobalt-infused M35 steel, heat-treated for high wear and heat resistance, and features a 135° split point that self-centers flawlessly on stainless steel and cast iron. The fully ground construction ensures a smooth cutting action, reducing friction and boosting speed—especially noticeable during continuous drilling in metal plates.

In side-by-side tests with single premium bits, the BECOLLO set held its own, delivering clean, round holes with minimal wandering. The plastic case keeps bits organized and protected, and the ANSI B94-11M compliance guarantees dimensional accuracy for reliable fit in precision tooling. While they don’t have flashy coatings, their bare cobalt finish means no risk of coating flaking during sharpening. They perform well in wood and plastic but truly shine in hard metals, where their edge retention outlasts standard HSS.

Compared to the 12-pack from the unnamed M35 brand, BECOLLO offers slightly better build consistency and a more durable case, though it includes fewer pieces. It’s the ideal middle ground for hobbyists, auto techs, and small shops needing reliable cobalt bits without overstocking. It delivers professional performance and smart packaging at a competitive volume price.

The uxcell M35 cobalt bit is a precision-engineered all-rounder built for users who need one bit to conquer everything from cast iron to copper. Crafted from M35 cobalt steel, it offers exceptional hardness and heat resistance, making it a top performer in stainless steel and hardened alloys—materials that quickly dull lesser bits. The 135° external point angle delivers fast, clean starts with minimal walking, while the optimized flutes efficiently eject chips, preventing clogging during deep or continuous drilling.

In real-world use—drilling through exhaust manifolds, aluminum housings, and PVC-lined enclosures—the uxcell bit handled transitions between materials smoothly, maintaining edge sharpness over dozens of holes. At 4 inches long, it offers solid reach for most handheld drills, and the smooth finish reduces friction, enhancing cutting speed. However, it demands coolant during prolonged use, as overheating can shorten lifespan despite its heat-resistant design. It’s less ideal for high-volume production but excels in mixed-material jobs.

Against the Diablo Metal Demon, the uxcell bit matches closely in stainless steel performance but lacks the proprietary thermal shield coating. It’s better suited for DIYers, auto repair, and fabrication shops handling diverse materials in moderate volumes. It delivers versatility, durability, and clean drilling with a focus on broad compatibility and consistent results.

The Yellow Paw 15/64-inch cobalt bit is the budget-savvy contender—a 3-pack that punches above its price with TiAlN-coated M35 cobalt steel, delivering industrial-grade hardness in a compact, no-frills package. The 5% cobalt core ensures heat resistance, while the titanium aluminum nitride (TiAlN) coating dramatically boosts surface hardness and oxidation resistance—helping it outlast uncoated cobalt bits in repetitive drilling tasks. The 135-degree split point locks onto metal surfaces instantly, eliminating walking on stainless or hardened steel.

In testing, these bits drilled cleanly through mild steel, aluminum, and even thin cast iron plates, with noticeably less heat buildup than standard HSS. At 3-1/2 inches long with a 2-inch flute, they offer balanced reach and rigidity, ideal for handheld drills in tight spaces. The rounded shank fits most chucks securely, and the included plastic case keeps them organized. While not intended for aerospace alloys, they handle most shop and garage tasks with confidence.

Compared to the BECOLLO 10-piece set, this pack offers fewer bits but a superior coating for the price. It’s perfect for home mechanics, weekend warriors, and small repair shops needing a few high-performing bits without overspending. It delivers strong durability and smart design with the added peace of mind of a US-based support team.