Drill Bits

A drill bit is only as good as the match between what it’s made of and what you’re drilling. Get that pairing wrong and you’ll burn through bits, overheat the cutting edge, and waste money. Get it right and a single bit lasts through jobs that would chew up the wrong tool.

Three things decide whether a bit performs: the material it’s made from, the shank that seats in your chuck, and the tip geometry that determines how it starts and clears chips. Nail those three and the rest is just picking a diameter.

For Montana work that runs from wood framing to metalwork to the occasional masonry hole, the choice usually comes down to three families — black oxide for general-purpose drilling, cobalt for hard metals, and carbide-tipped multi-material for everything in between.

Bit Material: Black Oxide vs. Cobalt vs. Carbide Multi-Material

This is where the real money decision lives. Buyers routinely overpay for cobalt when black oxide would do, or under-buy with a twist bit when they’re really drilling concrete.

Black oxide is the workhorse. Black oxide bits like Thunderbolt drill metal, wood, and PVC, and are recommended for use with portable drills. The web features a thicker core than a standard drill bit to provide strength and protect against side-load breakage. The coating earns its keep in this climate too — the black oxide finish provides lubricity and resists corrosion of the bit. That corrosion resistance matters where moisture and seasonal humidity swings sit on tools between jobs.

Cobalt is the step up for hard metal. The Red Helix Cobalt bit is engineered for extreme durability and longer life in hard metal applications. The cobalt alloy provides up to 15X life vs. black oxide drill bits, and is ideal for tough applications. If you’re drilling stainless steel or alloys regularly, this is where the extra cost pays back. It handles hard metal, PVC and wood. For general wood and PVC, though, you’re paying for capability you won’t use.

Carbide multi-material is the do-everything option. SHOCKWAVE Impact Duty Carbide Multi-Material bits are designed to tackle brick, block, concrete, steel, aluminum, ceramic tile, backerboard, wood, PVC, and drywall. The aggressive multi-grind carbide tip delivers up to 10x longer life in stacked materials and up to 85% faster drilling speeds in metal. One caveat worth knowing before you buy: these are not recommended for porcelain tile, though they are available in diameters up to 1/2 inch.

Material	Best for	Key advantage
Black oxide	Metal, wood, PVC	Corrosion-resistant coating, thicker web
Cobalt	Hard metals, stainless, alloys	Up to 15X life vs. black oxide
Carbide multi-material	Brick, block, concrete, steel, tile, wood, PVC, drywall	Up to 10x life in stacked materials, up to 85% faster in metal

Shank, Tip, and Flute — Why the Details Decide the Job

A bit that doesn’t seat fully in the chuck slips, strips, and rounds off. Match the shank to your tool before anything else.

For impact drivers and quick changes, you want hex. The SHOCKWAVE multi-material bits use a 1/4” hex shank, compatible with impacts, drill/drivers, and hammer drills. Step bits use the same setup — the 1/4 in. hex shank allows for fast bit change in impact drivers and sure grip in chucks. That cordless compatibility matters on remote jobsites where you’re running off batteries.

Twist bits use round or flatted shanks to fight slippage. The 3-Flat Secure-Grip shank holds the bit firmly in the drill chuck. On the cobalt line, smaller diameters run round shanks while larger bits step up to a 3/8” Reduced 3-Flat, and a 3-Flat Secure-Grip helps keep the bit fixed within the chuck.

Tip geometry decides whether a bit walks or starts clean. The 135° split point tip delivers a precision start and prevents walking for fast, accurate holes. That’s true across the lines — the cobalt bits use the same 135° split point for a precision start and no walking in hard metal, PVC and wood.

Flutes handle the chips. Clogged flutes mean heat, and heat kills bits. A parabolic flute form clears chips fast on the black oxide bits. The cobalt line takes a different approach to the same problem: a variable helix with an aggressive 35° helix angle that ends at 15° for rapid material extraction. Cobalt also adds a tip refinement — a Quad Edge tip designed to decrease heat build up and drill faster.

Step Bits — The Right Tool for Sheet Metal

When you’re drilling thin metal, a twist bit grabs, walks, and tears. A step bit solves that specific problem and does it with one tool covering multiple hole sizes.

The single cutting edge design gives more control and a cleaner finish. They’re made of high speed steel, durable and designed to drill through most metals, with a black oxide finish that prevents corrosion and works well with drilling lubricants. No more walking on contact — the speed start tip prevents bit walking and allows faster penetration.

The marking system takes the guesswork out of hole sizing: laser etched markings mean you always know your hole sizes. For cordless crews, the battery math is real — a dual-flute design optimized for cordless drills delivers 2X faster cutting and up to 50% more holes per battery charge. Fewer battery swaps in the field is no small thing when the truck’s a long walk away.

Step bits come in a wide range of size spans. Configurations run from 1/8”–1/2” to 1/4”–1-3/8” and 3/16”–7/8”, with step counts ranging from a single step up to 13 steps per bit.

Diameter, Length, and Sets vs. Singles

For everyday drilling, twist and cobalt bits cover the standard fractional range. Both the Thunderbolt black oxide and Red Helix cobalt lines span 1/16” up to 1/2” in fractional increments. They sell individually or in packs — the black oxide bits come in 1-pack, 6-pack, and 12-pack quantities.

For deep or layered drilling, the multi-material bits go longer. SHOCKWAVE multi-material bits are available in diameters up to 1/2 inch, with lengths running 3.5”, 6”, and 12”.

Western Building Center’s lineup covers the spread. There are black oxide twist bits in singles and sets — including a 3/8” Thunderbolt black oxide 6-pack and a 1/4” Thunderbolt black oxide 12-pack — plus a 15-piece black oxide set. Cobalt shows up as individual sizes and sets, including a 6-piece Cobalt Red Helix set for drill drivers and a 19-piece Red Helix cobalt metric set for hard metal applications. SHOCKWAVE titanium bits run from 1/16” up through larger fractional sizes, with a 23-piece SHOCKWAVE set spanning 1/16”–1/2” and a 7-piece SHOCKWAVE Impact Duty titanium set. For pulling wire and cable through framing, there’s also a 1” x 54” flexible cable auger bit. Some items come by special order.

A practical rule on sets versus singles: buy the set if you’re outfitting a kit or you drill a range of sizes regularly. Buy singles to replace the ones you actually wear out — and in this climate, the small diameters in metal go first.

Frequently Asked Questions

What’s the difference between black oxide and cobalt drill bits? Black oxide is general-purpose, built for metal, wood, and PVC, with a thicker web for side-load strength and a coating that resists corrosion. Cobalt is an alloy engineered for hard metals like stainless steel and alloys, delivering up to 15X the life of black oxide. For everyday wood and light metal, black oxide does the job. Step up to cobalt when you’re regularly drilling hard metal.

Can one bit drill both metal and masonry? Yes — carbide-tipped multi-material bits handle brick, block, concrete, steel, aluminum, ceramic tile, backerboard, wood, PVC, and drywall. They run up to 85% faster in metal than standard masonry bits and last up to 10x longer in stacked materials. They are not recommended for porcelain tile, so reach for a different bit there.

What shank do I need for an impact driver? A 1/4” hex shank. It locks into impact drivers for fast changes and seats securely in standard chucks. Both the SHOCKWAVE multi-material bits and the step bits use a 1/4” hex shank. Rotary hammers are a separate category and require SDS-Plus or SDS-Max shanks.

Why does my bit wander when I start a hole? That’s walking, and the fix is tip geometry. A 135° split point tip starts on contact and prevents walking for accurate hole placement. Step bits use a speed start tip for the same reason. If your bit is wandering, you’re either using a tip that isn’t designed to self-start or you’re not letting the point bite before applying pressure.

When should I use a step bit instead of a twist bit? Step bits are for clean, multi-size holes in sheet metal — work that twist bits do poorly because they grab and tear. A step bit’s single cutting edge gives more control and a cleaner finish, and one bit covers multiple hole sizes with laser-engraved reference marks for sizing. For cordless crews, they cut up to 2X faster and deliver up to 50% more holes per battery charge.

Do drill bits matter in cold weather? The bit itself is steel, but the corrosion-resistant coatings — black oxide and titanium — matter for tools that sit through Montana’s moisture and humidity swings. And for battery work in the cold, hex-shank bits and step bits that maximize holes per charge cut down on battery swaps when you’re working far from the truck.