A router is only as useful as its bit collection. The router body provides the motor and the speed — the bit determines what the tool actually does. Straight bits cut grooves and dados. Roundover bits shape edges. Flush-trim bits follow templates. Each bit type solves a specific problem, and understanding the common types means knowing which bit to grab for any routing task.

Router Bit Basics

Bit Anatomy

Every router bit has the same basic components: a shank (1/4 or 1/2-inch diameter) that mounts in the router collet, a body, and cutting edges (flutes). Some bits have a bearing guide that follows an edge or template to control the cut.

1/4-inch vs 1/2-inch shank: Always use 1/2-inch shank bits when your router accepts them. The larger shank is stiffer, vibrates less, deflects less under load, and produces cleaner cuts. 1/4-inch shank bits are for lighter-duty work and smaller routers.

Carbide vs HSS: Carbide-tipped bits stay sharp 10 to 20 times longer than high-speed steel (HSS) and handle hardwoods and abrasive materials without dulling quickly. Buy carbide for any bit you use frequently. HSS is adequate for occasional softwood work.

Essential Bits for a Home Workshop

Straight Bit

A cylindrical bit that cuts flat-bottomed grooves, dados, and mortises. The most basic and most used router bit.

Common sizes: 1/4, 3/8, 1/2, and 3/4-inch cutting diameter.

Uses:

Cutting dados (grooves across the grain) for bookcase shelves
Cutting grooves (with the grain) for panel assemblies
Mortises for joinery
Template routing with a guide bushing
Flattening surfaces with a router sled

The 1/2-inch straight bit is the single most used bit in most shops. Buy a quality one (Freud, Whiteside, Amana) for $12 to $20 and it lasts years.

Roundover Bit

Creates a rounded edge profile. Available with different radius sizes — 1/8, 1/4, 3/8, and 1/2-inch radius are the most common. A bearing on the bottom rides along the edge and controls the cut depth.

Uses:

Softening sharp edges on furniture, shelves, and trim
Full bullnose profile (using a roundover on both top and bottom edges)
Edge treatment on tabletops and counters

A 1/4-inch roundover is the most versatile single edge-profiling bit. It creates a gentle, comfortable edge that removes sharp corners without making the edge look overly decorative.

Flush Trim Bit

A straight bit with a bearing that matches the cutting diameter exactly. The bearing follows a template or existing edge while the cutter trims the workpiece flush.

Uses:

Trimming laminate flush with a substrate
Pattern routing — attach a template to the workpiece and the bit follows the template shape exactly
Trimming edge banding flush with the plywood face
Making multiple identical parts from a single template

The flush-trim bit is essential for any router table setup. A 1/2-inch diameter, 1-inch cutting length bit ($15 to $20) handles most tasks.

Chamfer Bit

Cuts a 45-degree bevel along an edge. Bearing-guided. Creates a clean, angled edge treatment that looks intentional and hides minor edge imperfections.

Available in different sizes that determine the chamfer width. A 45-degree, 1/4-inch chamfer is the most common.

Rabbeting Bit

Cuts a step (rabbet) along an edge. The bearing controls the rabbet width, and the bit height controls the rabbet depth. Used for back panels on cabinets, glass panel recesses in doors, and lap joints.

Many rabbeting bits come with a set of interchangeable bearings that produce different rabbet widths (1/4, 5/16, 3/8, 7/16, 1/2-inch) from the same bit. This bearing set ($20 to $30) replaces five individual bits.

Cove Bit

Cuts a concave (inward-curving) profile along an edge. The opposite of a roundover — where a roundover is convex, a cove is concave. Used for decorative trim, crown molding profiles, and furniture edge details.

Roman Ogee Bit

Creates an S-shaped profile with a stepped shoulder. The classic decorative edge for traditional furniture and trim. Used on tabletop edges, frame profiles, and door panel edges.

Slot Cutting Bit

A thin disc-shaped cutter that plunges into the wood edge and cuts a narrow slot. Used for biscuit joint slots (as an alternative to a biscuit joiner), T-molding slots, and panel connectors.

Bit Speed Guidelines

Larger bits must run slower. A 3-inch raised panel bit spinning at 22,000 RPM exceeds safe rim speed and can shatter. Follow these guidelines:

Bit Diameter	Maximum RPM
Up to 1 inch	24,000
1 to 2 inches	18,000
2 to 2.5 inches	16,000
2.5 to 3.5 inches	12,000

Set the router speed dial before installing the bit. Variable speed is essential for router table work where larger bits are common.

Feed Direction

When routing freehand (handheld router), move the router so the bit rotation pushes against the feed direction. On the outside of a workpiece, this means moving the router counterclockwise (when viewed from above). On the inside of a cutout, move clockwise.

On a router table, feed the workpiece from right to left (against the bit rotation). Feeding in the wrong direction (climb cutting) causes the bit to grab the workpiece and pull it through uncontrollably.

Buying Strategy

Start with five bits and add specialty bits as projects demand:

1/2-inch straight bit — dados, grooves, mortises
1/4-inch roundover — edge softening
1/2-inch flush trim — template work, laminate trimming
Rabbeting bit with bearing set — back panel rabbets, joints
45-degree chamfer — decorative edge treatment

These five bits handle 80 percent of home workshop routing tasks. Total investment: $60 to $100 for quality carbide bits from Freud, Whiteside, or Amana.

Avoid the cheap 15 or 30-piece bit sets ($20 to $40 for the set). They include dozens of profile bits you will never use, and the carbide quality is poor — they dull quickly and produce rough cuts. Buy fewer, better bits in the profiles you actually use.

Maintenance

Keep router bits clean. Pitch and resin buildup on the flutes reduces cutting performance and causes burning. Clean bits with a brass brush and a spray of blade cleaner (CMT Formula 2050) after every few uses.

Store bits in a dedicated case or block with individual holes. Bits rolling around in a drawer chip each other and dull the cutting edges.

Bottom Line

Five quality carbide bits cover most routing tasks in a home workshop. Buy 1/2-inch shank, carbide-tipped bits from reputable manufacturers. Learn the speed guidelines for larger bits. Feed against the rotation. Keep bits clean. The router becomes exponentially more useful with each new bit you add to the collection — and every bit pays for itself on the first project where it saves time or creates a profile you could not achieve otherwise.