Specialty Bits

Specialty bits split into two families that get confused all the time. Driver bits apply torque to screws — they’re the interface that transfers torque from a tool like a screwdriver, t-handle, or drill to the mating recess on top of a threaded fastener, and they’re frequently interchangeable across diameters and lengths. Drill bits cut holes. Different job entirely.

The buying decision that matters most? Match the bit to your material. Get it wrong and you’ll crack tile, strip a screw, dull a bit in seconds, or burn out a drill motor. Using the wrong bit can crack tile, strip screws, or burn out your drill motor. Specialty bits reduce stress on your drill and prevent damage to surfaces and tools.

Two questions answer most of it. What are you drilling or driving into? And what shank does your tool accept? Sort those out before anything else.

Match the Bit to the Material

This is the core of it. Every job has a right bit, and the material dictates the choice.

Wood. Three workhorses cover most carpentry. Woodworkers love brad point bits for their pinpoint accuracy. Unlike twist bits, the pointed tip ensures the bit doesn’t wander when you begin drilling, which means cleaner holes and less splintering. When you need a flat-bottom hole — concealed hinges, inlays — reach for a Forstner. With a circular rim and center spur, it’s perfect for clean, precise holes in wood. These bits are best used with a drill press or hand drill at slow speeds for clean results without burning the wood. For fast rough boring, spade bits earn their keep. Spade bits are paddle-shaped and designed to quickly remove material from softwoods and plywood — running wiring through studs, rough carpentry, that kind of work. Not ideal for fine furniture unless you like jagged edges and tear-out.

Metal. The standard twist bit handles the easy stuff. High-Speed Steel (HSS) twist drill bits are the most widely used drill bit in the world. The helical flute design evacuates chips while the ground tip shears material with a rotating cutting edge. HSS bits handle a huge range of materials — from softwood and plastic to mild steel and aluminum. But HSS hits a wall on stainless and hardened steel. That’s where cobalt comes in. Cobalt drill bits are HSS bits with 5-8 percent cobalt alloyed into the steel itself (not a coating). The cobalt raises the red-hardness temperature, allowing the bit to maintain a sharp cutting edge at temperatures where standard HSS would soften and fail. This makes cobalt bits essential for stainless steel, titanium, Inconel, and other heat-resistant alloys.

Two cobalt grades to know. M35 (5% cobalt) handles most austenitic stainless steels (304, 316), medium-carbon steel, and heat-treated alloys up to roughly 35 HRC. M42 (8% cobalt) is for the toughest jobs: Inconel, Hastelloy, hardened steel up to 45 HRC, and heavily work-hardened stainless.

Masonry and concrete. Carbide tip, no exceptions. SDS hammer drill bits are the professional standard for drilling concrete, reinforced concrete, masonry block, and natural stone. The key feature is the SDS shank — a slotted system that locks into a rotary hammer and transmits percussive energy directly to the carbide tip while allowing the bit to slide axially inside the chuck. Standard HSS doesn’t stand a chance here — it dulls instantly with no carbide tip.

For brick and light block, round-shank masonry bits in a regular drill get the job done. Round-shank masonry bits fit standard 3-jaw keyless chucks on conventional drills. They have the same brazed carbide tip as SDS bits but rely on the drill’s internal hammer mechanism for percussion — which delivers far less impact energy than a dedicated rotary hammer. They work on brick, aerated block, lightweight concrete, mortar joints — adequate for hanging picture frames, curtain rails, and light anchors. Push past that into dense concrete and you’ll regret it. The bit overheats, the carbide tip cracks or detaches, and the hole barely progresses. If you are drilling more than a few holes in concrete, switch to an SDS-Plus rotary hammer.

Glass and tile. Slow down and keep it wet. Glass and tile bits usually feature a spear-point tip and are made from hardened carbide to handle delicate surfaces. Keep the surface wet while drilling to reduce heat and prevent cracks. Western Building Center carries carbide glass and tile bits in 1/8”, 3/16”, 1/4”, 5/16”, 3/8”, and 1/2” sizes, along with a 4-piece glass and tile bit set.

Shank and Tool Compatibility — Confirm Before You Buy

This is the mistake that wastes the most money. The shank has to match the tool, period.

SDS comes in two families, and they don’t cross over. SDS-Plus is a 10 mm shank with 4 grooves. Fits rotary hammers up to roughly 4 kg / 3.5 J. Covers drill diameters from 4 mm to 26 mm. The most common system for construction, electrical, and HVAC trades. Step up to the heavy work and you need SDS-Max. SDS-Max is an 18 mm shank with 5 grooves. Fits heavy-duty rotary hammers from 5 kg upward (5-27 J). Covers diameters from 12 mm to 52 mm and beyond. Required for deep anchoring, core drilling, and heavy demolition.

Don’t try to force an SDS bit into a regular chuck. It won’t work and you’ll wreck both ends of the deal. Round-shank masonry bits will fit a standard chuck, but they deliver far less impact energy than a rotary hammer — fine for light masonry, useless on dense concrete.

For driving, the 1/4-inch hex shank is the one to know. Some of the most common specialty screwdriver bits simply have a 1/4-inch hex shank at the end that flares in and then back out again. These fit just fine in multi-bit screwdrivers and drills, but they’re specifically designed to fit the collet of an impact driver.

Specs That Separate a Bargain Bit From One That Lasts

The markings on a bit tell you what it’ll survive. Three things matter: grade, point geometry, and coating.

Spec	What it means
Rolled HSS	Formed by rolling, then heat-treated. Adequate for softwoods, plastics, and mild steel. Lower cost, shorter service life, wider tolerances. Common in consumer-grade sets.
HSS-G (ground)	Flutes and point are precision-ground after hardening. Sharper cutting edges, tighter diameter tolerances (h8), and significantly longer tool life. The professional standard.
Cobalt M35 / M42	5-8 percent cobalt alloyed into the steel itself. Maintains a sharp edge at temperatures where standard HSS would soften and fail.
118° point	Standard for general use.
135° split point	Self-centers without a pilot hole and reduces the axial thrust that causes work-hardening.

On hard metals, the point angle matters as much as the grade. Avoid cobalt bits with 118-degree conventional points on stainless. Go 135° split point.

One more habit that kills bits early: too much RPM on steel. HSS overheats above approximately 600 degrees Celsius, losing its hardness permanently. Use the correct RPM chart and apply cutting fluid on ferrous metals.

On the driving side, the drive geometry is its own decision. Slotted and Phillips drives are the most common, while hex socket (Allen), square (Robertson), and hexlobe (Torx) are also readily available. Square bits show up everywhere in one trade in particular — very common in the electrical trade, square bits are exactly what they sound like — 4 flat sides of equal length. Torx earns its reputation. Torx bits (or star bits) have 6 points instead of flat sides. These provide much better grip security than standard bits and are widely used around the trades.

Watch the look-alikes. Pozidriv fools people every day. Pozidriv looks very similar to a Phillips head at first glance. The telltale difference is smaller ribs moving into each corner created by the cross arms. The big deal is that the two types aren’t interchangeable despite how similar they may appear.

Problem-Solving Bits Worth Keeping Around

A few specialty bits do jobs a standard bit simply can’t.

Step bits are the multi-tool of the bunch. With a conical shape and graduated steps, it’s designed to drill multiple hole sizes without changing bits. It’s a lifesaver when working with thin metals, plastics, or sheet material. Western Building Center’s reference for that category includes options like a 3/16 in. to 7/8 in. step bit with 12 steps. Use at slower speeds to avoid overheating.

Drill-tap bits collapse two steps into one. Drill and tap holes in one step. Includes SAE and UNC sizes. Saves time and effort during installation.

Installer bits reach where nothing else will. Long-reach bits for wiring, cable routing, or drilling behind walls. Extended shaft with 12-24 in. options. 10mm-7/16 in. diameter options.

A broken fastener doesn’t have to end your day. Left hand drill bits reverse bit direction to remove broken fasteners while drilling.

For cabinetry and joinery, two more pull their weight. Hinge drill bits use a spring-loaded self-centering guide, ideal for furniture and cabinetry. And pocket hole drill bits drill angled holes for pocket hole joinery, used with jigs.

Frequently Asked Questions

What’s the difference between a drill bit and a driver bit? A drill bit cuts a hole. A driver bit turns a fastener. Driver bits are the interface that transfers torque from a tool to the mating recess on top of a threaded fastener — the tip inserts into a depression machined into the top of the screw head in a male tool / female fastener configuration. Drill bits remove material to open a hole.

Can I use an HSS twist bit on concrete? No. HSS bits don’t work on concrete or masonry — they dull instantly because there’s no carbide tip. Concrete needs a carbide-tipped bit, and for anything beyond a few holes, an SDS-Plus rotary hammer.

Why does my bit dull so fast on stainless steel? Standard HSS softens under the heat stainless generates. Cobalt raises the red-hardness temperature, letting the bit hold its edge — M35 (5% cobalt) handles 304 and 316 stainless up to roughly 35 HRC. Pair it with a 135° split point and cutting fluid.

Will an SDS bit fit my regular drill? No. SDS-Plus and SDS-Max shanks lock into rotary hammers, not a standard 3-jaw chuck. Round-shank masonry bits fit a regular chuck, but they rely on the drill’s internal hammer mechanism, which delivers far less impact energy than a dedicated rotary hammer.

What keeps tile from cracking when I drill it? A carbide spear-point bit and water. Glass and tile bits feature a spear-point tip made from hardened carbide for delicate surfaces. Keep the surface wet while drilling to reduce heat and prevent cracks. Go slow.

Which point angle should I buy — 118° or 135°? For general drilling, 118 degrees is standard. For harder metals, a 135-degree split point self-centers without a pilot hole and reduces the axial thrust that causes work-hardening.