Router Bit: Types, Uses, and Tips for DIY Woodworking

What Is a Router Bit?

A router bit is the cutting head you install in a handheld or table-mounted router to remove material from wood and some plastics. The bit’s shape determines the cut it makes—anything from a straight groove to a rounded edge or an intricate decorative profile. Most bits have a steel shank that clamps in the router’s collet and carbide cutting edges that stay sharp longer and stand up to abrasive materials like plywood and MDF.

How a Router Bit Works

The router motor spins the bit at very high speed (often 10,000–25,000 RPM). As you move the tool along the workpiece, the cutting edges shave away material. For clean, controlled results, you feed the router against the bit’s rotation so the cutter pulls itself into the wood gently rather than grabbing and running. Light passes, steady speed, and a firm grip produce the best surface.

Common Uses in DIY and Home Projects

Edge profiling: Add a smooth round-over to a shelf, a cove on a mantel, or a decorative ogee on cabinet doors.
Trimming and template work: Use a flush-trim bit with a bearing to copy a template, trim laminate, or make identical parts.
Joinery: Cut dados (grooves across the grain), rabbets (steps on an edge), and dovetails for drawers and boxes.
Hinge and hardware mortises: Rout shallow pockets for hinges, strike plates, and pulls.
Sign making and detailing: V-groove and round-nose bits add letters, lines, and accents.

Types of Router Bits

There are many profiles; here are the most common for home projects:

Straight bit: Makes grooves, dados, and mortises. A go-to for shelving dados and hinge pockets.
Flush-trim bit (bearing-guided): A top or bottom bearing rides along a template or a finished edge to trim another piece perfectly to size (great for laminate and pattern routing).
Chamfer bit: Cuts a straight, angled bevel along an edge for a crisp, modern look or to break sharp corners.
Round-over bit: Softens edges to a specific radius. Ideal for shelves, tabletops, and handrails.
Cove bit: Cuts a concave scoop. Often paired with a round-over for classic furniture edges.
Rabbeting bit (bearing-guided): Creates a step along an edge; bearings of different diameters set the rabbet width.
Dovetail bit: Used with a jig to make dovetail joints for drawers and boxes.
V-groove bit: Cuts a V-shaped groove for signs and accents; also used to create chamfered lines.
Round-nose/Core box bit: Makes semicircular grooves for fluting or wire management.
Spiral bits (upcut, downcut, compression): Straight-cut bits with helical flutes. Upcut clears chips well but can lift veneer; downcut pushes fibers down for cleaner tops; compression combines both for plywood and laminates.

Bearing-Guided vs. Non-Bearing

Bearing-guided bits follow a template or the workpiece edge for consistent cuts without a fence.
Non-bearing bits rely on a fence, guide bushing, or edge guide to control the path.

Shank Size and Materials

Shank sizes: 1/4-inch and 1/2-inch are most common. A 1/2-inch shank is stiffer and runs smoother, reducing chatter. Use the largest shank your router accepts.
Cutting materials: Carbide-tipped bits hold an edge longer than HSS (high-speed steel) and are a solid choice for most DIY tasks. Solid carbide spiral bits excel in plywood and MDF.

Choosing the Right Bit

Match the profile to the job: round-over for soft edges, rabbet for casework, straight bit for grooves.
Choose bearing-guided bits for template work and trimming; non-bearing bits for fence-guided grooves and joinery.
Prefer 1/2-inch shank versions of commonly used bits for smoother cuts, if your router supports them.
For plywood, laminates, and MDF, select carbide or solid carbide spiral bits to resist wear and reduce tear-out.
Check the maximum cut depth and radius to ensure the bit can make the cut you need.

Safety and Good Technique

Wear eye and hearing protection and connect dust collection when possible.
Secure the workpiece with clamps. Keep hands clear of the bit and never rout small parts by hand—use a router table or a jig.
Insert the bit’s shank fully, then pull it out about 1/16–1/8 inch before tightening the collet; this prevents bottoming out and improves grip.
Set the correct speed: smaller bits can run faster; large bits need slower speeds to prevent burning and vibration. Follow the bit maker’s guidance.
Make multiple shallow passes rather than one deep cut. Your router works less, and the cut will be cleaner.
Feed against the bit’s rotation. On a handheld router, moving left-to-right across the far edge or right-to-left across the near edge keeps control. Avoid climb cutting unless you understand the technique and use very light passes.

Care and Maintenance

Clean resin and pitch buildup with a bit cleaner or mineral spirits and a soft brush. Gunk makes bits run hot and burn the wood.
Inspect the bearing. If it feels rough or wobbly, replace it before it fails mid-cut.
Sharpen lightly with a fine diamond card on the flat faces of carbide cutters, or have a sharpening service touch them up.
Protect the edges by storing bits in a holder or case. Avoid letting cutters bang against metal or other bits.
Maintain the router collet: keep it clean and replace a worn collet if it won’t hold securely.

Common Mistakes to Avoid

Using the wrong shank size for your collet, or not tightening the collet fully.
Taking too deep a pass, causing burning, chatter, or kickback.
Running a dull or dirty bit, which overheats and leaves a rough surface.
Pushing the router too slowly (burn marks) or too fast (tear-out and chatter).
Routing end grain first without backing support, which can blow out corners; do the end grain, then the long grain to clean up.
Trimming small parts freehand instead of using a router table, featherboards, or jigs.

Related Terms

Router, trim router, router table
Collet: the clamp that holds the bit’s shank.
Template/guide bushing/edge guide: devices that control the router’s path.
Dado, rabbet, mortise, profile: common cut types.

Practical Examples

Soften a shelf edge: Install a 1/4-inch round-over bit with a bearing. Set a modest depth so the bearing just contacts the edge. Make two light passes around the shelf, sanding lightly after.
Trim laminate flush: After bonding laminate to a countertop, use a flush-trim bit with the bearing riding the substrate. Move steadily and keep the base flat to avoid gouges.
Cut a 3/4-inch dado for a bookshelf: Clamp an edge guide or straight board parallel to your cut line. Make two passes with a 3/8-inch straight bit to reach full width, clearing dust between passes.
Make a clean rabbet for a back panel: Use a rabbeting bit with the bearing that matches your desired width. Take two passes to reach full depth, checking fit with the panel as you go.

With the right router bit, a basic router can shape edges, cut precise joinery, and duplicate parts accurately, opening up a wide range of clean, professional-looking results in home projects.