Router Bits

A router bit is the shaped cutter that mounts in a router’s collet and spins fast enough to shear wood fibers into a profile. Bits come in three families — profile, joinery, and template — with dozens of variants, but five bits cover 90% of furniture and cabinet work: a straight bit, roundover, flush-trim, rabbeting set, and chamfer. Start there. Buy specialized profiles later, when a specific cut demands one.

Here’s the thing most beginners get wrong: they buy a giant ten-piece set from an unknown brand and wonder why the cuts burn. Quality matters more than quantity. One quality bit cuts cleaner than a cheap ten-piece set from an unknown brand. Two variables drive that quality — shank size and carbide grade. Whenever possible, use bits with 1/2-inch shank bits. They provide better stability with less vibration, and they typically produce a smoother cut and have longer cutter life. And most of the profile bits will have carbide cutters, which are harder than steel and will hold an edge longer — 10 to 25 times longer — but also are more brittle.

The Five Starter Bits and What Each One Cuts

Buy these in order. Each adds a category of cut, and by the fifth you can handle dadoes, profiled edges, template work, rabbeted panels, and chamfered corners — the working vocabulary of furniture and cabinet joinery.

Straight bit. If you buy one bit, make it this. A straight bit cuts flat-bottomed channels: dadoes for shelf pins, grooves for drawer bottoms, mortises for loose-tenon joinery, pockets for inlays and hardware. Get it in 1/2-inch diameter with a 1/2-inch shank. That size handles the most common structural work and stays stable in hardwoods without chatter. Western Building Center carries 2-flute straight bits across the working range — 1/4-inch, 3/8-inch, 1/2-inch, 3/4-inch, and a full 1-inch — so you can match the bit to the groove width.

Roundover bit. The workhorse. The highest-use bit in most shops. A roundover softens sharp edges on every project: tables, shelves, cabinet doors, cutting boards. A 1/4-inch radius is the right starting size. You’ll eventually want a 3/8-inch radius too, but not yet. The bearing rides the workpiece edge and controls depth automatically. Adjust to show just the curved portion, or leave a small fillet shoulder for a different look. The stock list includes roundover profiles at 1/4-inch, 5/8-inch, and 3/4-inch.

Flush-trim bit. A flush-trim bit carries a bearing the same diameter as the cutter. Run the bearing against a template or existing edge and the cutter shaves whatever’s proud of it perfectly flush. Once you can route to a template, you produce ten identical curved parts in the time it takes to hand-shape one. It’s also essential for trimming solid-wood edge banding flush with plywood. Available in 2-flute and 3-flute 1/2-inch configurations, plus top-bearing pattern versions.

Rabbeting set. A rabbeting bit cuts an L-shaped notch along the edge of a board. Cabinet backs drop into rabbets. Box lids fit over them. Panel frames use them to hold glass or inset panels. Get one with multiple interchangeable bearings. A single bit body gives you different rabbet depths by swapping the bearing. One body, four uses. The multi-rabbet set and assorted bearing packs handle exactly this — the Rabbet router bit is ideal as it has a circular pilot bearing that acts as a guide riding along the edge of the cut material.

Chamfer bit. A chamfer cuts a flat bevel along the edge. 45 degrees is the most common angle. It reads sharper and more modern than a roundover. Good for cutting boards, boxes, and contemporary furniture. It does double duty too — cut a 45-degree bevel along two panel edges and glue them together for a clean, invisible corner joint.

Profiles, Shanks, and Carbide — What Actually Matters

Beyond the starter five, here’s the quick map of profile-to-cut. Keep it handy at the router.

Bit	What it cuts	Common uses
Straight	Flat-bottomed channel	Dadoes, grooves, mortises, pockets
Spiral upcut	Flat bottom, chips exit upward	Deep mortises in hardwood, cleaner bottom
Spiral downcut	Flat bottom, chips pressed down	Plywood top faces, veneer entries
Flush-trim	Edge flush to a bearing	Template routing, laminate trimming
Roundover	Convex quarter-circle	Furniture edges, softened corners
Cove	Concave quarter-circle	Decorative molding, shelf undersides
Chamfer	Flat angled bevel	Decorative edges, miter prep, box corners
Roman ogee	S-curve profile	Cabinet door edges, furniture borders
Rabbeting	L-shaped notch at edge	Cabinet backs, box lids, panel frames
Dovetail (14°)	Angled undercut channel	Sliding dovetails, drawer fronts

On spirals, direction is the whole game. Upcut bits have flutes that spiral up the bit as it cuts. As it cuts, the bit pulls the chips up and out of the groove. This means an upcut spiral bit can cut faster and run cooler. Unfortunately, this also means you are more likely to get some tear out on the top edge of your groove when cutting plywood or highly figured hardwood. Flip it for clean visible surfaces: downcut spiral bits have flutes that spiral downwards as it cuts. This blows the chips back down into the groove, which can cause the bit to heat up faster, but it means the top edge is sheared downward, resulting in almost no tear-out. Need both? Compression bits have teeth arranged in both upcut and downcut. The end of the bit is an upcut so that it pulls chips out of the bottom, while the rest of the bit is a downcut to give you a cleaner edge. They do require you to make a deep enough pass, so this isn’t the bit for thin material. The stock list carries both 1/4-inch up-spiral and down-spiral bits.

Quality you can judge before buying comes down to a few things. High-quality router bits have carbide cutters that have been sharpened to a fine edge and that are thick enough to allow for multiple regrindings. The brazing that joins the carbide tip to the bit will appear even. Anti-kickback design earns its keep — high-quality bits will incorporate a design that minimizes the risk of workpiece kickback. These anti-kickback bits have more body mass, and their enlarged bodies prevent the bits from biting too deeply and catching on the material. The greater body mass also helps to dissipate heat and keep the bits sharp longer.

Because carbide holds an edge but chips easily, handle it right. While carbide-tipped bits are preferable, you must handle and store them carefully to avoid chipping the cutters.

Running Bits Without Burning or Kickback

Routers turn fast. Router bits spin very fast (up to 30,000 RPM), so if they’re held in one place while cutting or go around a corner slowly, it’s common for the wood to burn slightly. The fixes are simple: when edge-forming, make the profile in two or three passes — remember the old adage, “A router cuts best when it cuts least.” Lower the speed if your router is equipped with a rheostat, and make sure the bit is sharp and clean.

Some bits are never safe in your hand. Some bits can be safely operated only in a table-mounted router with a variable-speed feature. If you want to make a cabinet with frame-and-panel construction, you’ll need to get or build a router table before you can safely use the stile-and-rail bits and panel-raising bits required for such a project. Glue-joint bits fall in the same camp — they are meant to be used exclusively in a router table. Using glue joint bits in a handheld router can result in uneven profiles or, worse, injury if the router binds up and kicks back on you.

Frequently Asked Questions

Which router bits should a beginner buy first? Five bits handle the bulk of furniture and cabinet work: a straight bit, a roundover, a flush-trim, a rabbeting set, and a 45-degree chamfer. These five profiles handle dadoes, softened edges, template work, rabbeted panels, and chamfered corners — the core vocabulary of furniture and cabinet joinery. Add specialized profiles only when a specific cut calls for one.

Is a 1/2-inch shank really better than 1/4-inch? Yes, wherever your router accepts it. 1/2-inch shanks offer greater stability, reduce vibration, and are preferred for larger bits, deeper cuts, and more powerful routers. Always use a 1/2-inch shank bit if your router accepts it, as it provides a cleaner cut and reduces the risk of bit breakage.

Carbide or high-speed steel? Carbide for almost everything. Carbide tip bits are more complex and hold their sharpness longer than HSS, meaning they have a longer lifespan. The trade-off is brittleness, so store and handle them with care.

Why does my wood burn when I rout? Usually the bit sat in one spot too long, moved too slowly around a corner, or you tried to hog off the full profile in one pass. Make the profile in two or three passes, lower the speed if your router has a rheostat, and make sure the bit is sharp and clean.

What’s the difference between a flush-trim and a pattern bit? Bearing position. A flush-trim carries its bearing at the bottom, riding the finished edge below. A pattern bit (sometimes called a pattern flush trim bit) is essentially a flush trim bit with the bearing at the top instead of the bottom. As the pattern bit goes around a pattern, it cuts whatever’s south of there.

When do I need a router table instead of a handheld router? For large, aggressive profiles. Some of these bits are small and are intended for use in a handheld router, but many of these bits are somewhat large and can be used safely only in a router table. Panel-raising, rail-and-stile, and glue-joint bits all belong in a table.