Why sales rank is a weak guide
A list of best sellers tells you what many people bought, not what suits your router or your projects. This article does not name brands or rank products. It explains the features that make router bits differ so you can read any listing with confidence.
Router bits cut at high speed, so quality and fit matter for both results and safety. Wear eye and hearing protection, keep your hands clear of the bit, and unplug the router or remove its battery before changing a bit.
Common profiles for edge work
The profile is the shape the bit cuts. A small set covers most work.
- Roundover. Softens a sharp edge into a quarter-circle. Probably the most commonly used decorative bit, and useful on anything that will be handled.
- Chamfer. Cuts a flat bevel, often at 45 degrees.
- Cove. Cuts a concave curve, the opposite of a roundover.
- Ogee and classical profiles. Combine curves for traditional edges on tabletops and moldings. They remove more wood and are best used in several light passes.
- Beading bits. Leave a small rounded bead along an edge.
Many of these come with a bearing at the tip or base. The bearing rides along the edge of the workpiece and sets how deep the profile cuts, which is why edge-profile bits are popular for freehand work with a handheld router. If you want to see how these are used in practice, the technique behind edge profiles is mostly about steady feed and light passes.
Bits for joint and shaping work
Other bits are chosen for function rather than decoration.
- Straight bits. Cut grooves, dados and mortises. Different diameters let you match plywood thicknesses, though real plywood is often a little under its nominal size, so test on scrap.
- Rabbeting bits. Cut a step along an edge, commonly with interchangeable bearings that change the width of the step.
- Flush-trim bits. Follow a template or an existing edge to trim material even with it.
- Dovetail bits. Cut angled slots for dovetail joints, usually paired with a jig. Angles vary, so match bit and jig.
- Slot cutters and tongue-and-groove sets. Used for panel and frame work, and for joining boards edge to edge.
- V-groove and round-nose bits. Used for decorative grooves, lettering and some inlay work.
A small collection of a straight bit, a roundover, a chamfer, a flush-trim and a rabbet handles a surprising amount of work. Buying a large set of seldom-used profiles can be less useful than a few good individual bits.
Shank size
The shank is the smooth cylinder that sits in the router collet.
- 1/4 inch shanks fit nearly every router, including compact trim routers. Because they are thinner, they can flex or vibrate more, especially in larger bits.
- 1/2 inch shanks are stiffer and generally give a smoother cut with less chatter, and they are better suited to larger diameters. They require a router with a 1/2 inch collet.
- Some routers use metric collets, so check your manual.
Never force a shank into a collet that does not match it. Use the collet made for the shank size, and insert the shank far enough to grip well without bottoming out, per the manual. A bit with a worn or scratched shank may slip. Keep the collet clean, too. Blade runout and chatter, which a sloppy fit makes worse, show up as rough cuts and burn marks.
Carbide quality
Most woodworking bits use carbide-tipped cutting edges brazed onto a steel body, which stay sharp far longer than plain steel. Solid carbide bits exist too, usually for small spiral and straight bits. Quality varies, and you can look for several signs.
- Carbide thickness. Thicker carbide can be sharpened more times, though price does not guarantee it.
- Edge finish. Carbide that looks evenly ground and polished usually cuts cleaner. Chips or rough grinding are warning signs.
- Body design. A well-balanced body reduces vibration. Larger bits often include features meant to limit how much wood the bit can take in a pass, which helps control the cut.
- Coatings. Some bits have non-stick coatings that resist pitch and resin buildup. These can help, but cleaning still matters.
- Bearing quality. A rough or sticky bearing can burn the wood or leave marks.
Because details differ by manufacturer, rely on the stated specifications and the manual rather than assuming a higher price means better steel or carbide.
Using bits safely and keeping them sharp
Large-diameter bits generally need lower speeds, and the manufacturer’s guidance for bit diameter and router speed should be followed. Variable speed controls make this easier, and the same ideas behind tool RPM settings apply here. Take shallow passes rather than one deep cut, since a heavy cut strains the bit, the router and your control.
Burn marks usually point to a dull bit, a feed that is too slow, or a dirty edge. Clean pitch with a cleaner suitable for router bits, following the product directions. Dull bits can often be sharpened by a professional service, though small or coated bits may not be worth it. Inspect each bit before use for chips, cracks and bent shanks, and discard any that are damaged.
A short buying checklist
- Confirm the shank size your router accepts.
- List the profiles and joints your next few projects need.
- Prefer a few well-made bits over a big set you will not use.
- Check carbide finish, bearings and the listed cutting dimensions.
- Match the bit diameter to your router and the speed ranges in your manual.
- Test every new bit on scrap wood before cutting the real piece.