Why a “top five” does not fit router bits
Router bits are not one product with five competitors. They are a family of shapes, each doing a different job, so a short bestseller list would mix a roundover bit with a straight bit and tell you very little. A better approach is to understand the shapes, then choose a small set that matches the work you do. This article gives that framework without naming brands.
A sensible starter set
Many home woodworkers can do a lot with a handful of bit types:
- Straight bits cut grooves, dados and rabbets, and hollow out pockets.
- Roundover bits soften edges to a rounded profile.
- Chamfer bits cut an angled edge.
- Flush-trim bits have a bearing that rides on a template or an existing edge so the cutter follows it exactly.
- Rabbeting bits cut a step along an edge, often with interchangeable bearings that change the depth.
Later additions might include ogee and cove profiles for decorative edges, a round-nose bit for grooves, and a bit for cutting slots. Profile-heavy sets look appealing, but many people find they use a few bits constantly and leave the rest in the case. Buy for the projects in front of you.
Shank size
The shank is the cylindrical part that fits into the router’s collet. Common sizes are quarter inch and half inch, and metric shanks also exist. Check which sizes your router accepts before buying; some routers come with one collet and need another for the other size.
Half-inch shanks are stiffer, tend to vibrate less and handle larger bits better. Quarter-inch shanks are common on smaller routers and smaller bits, and they are usually fine for light work. As a general rule, use the largest shank your router accepts, especially for big profile bits. Bits with large cutting diameters should not be used in routers not rated for them, and the manual will state limits. Cutter size also affects speed: the larger the diameter, the lower the recommended router speed, which ties back to the idea of tool RPM in general.
Carbide quality
Most home bits have carbide cutting edges brazed onto a steel body. Carbide stays sharp far longer than steel, but quality varies. Things worth looking at:
- The carbide tips should be thick enough to be resharpened rather than a thin sliver.
- Edges should look clean and even, without chips, pits or uneven grinding.
- The brazing between carbide and steel should look neat.
- The bit body should be balanced and well finished, since a poorly made body can vibrate.
High-speed steel bits exist and are sometimes used for light work or specialty profiles, but they dull faster in hardwoods and sheet goods. Cheap bits are not always bad, but very low prices often mean thin carbide that wears quickly or cracks. It can be more economical to buy fewer good bits than a large set of weak ones. The same attention to edge quality applies to sharpening in general; see the notes on keeping edges sharp.
Bearings, anti-kickback design and cutter geometry
Bearing-guided bits are easy to use on edges and templates. Check that the bearing spins freely and is not gummed with resin or dust. Replacement bearings are inexpensive, so a bad one is no reason to discard a bit.
Some bits are designed with extra body behind the cutter to limit how much wood the bit can take in one pass, which reduces the chance of a violent grab. These are often called anti-kickback designs, and they can be a sensible choice for beginners.
Cutter geometry also matters. Upcut spirals pull chips out of the cut but may tear the top surface. Downcut spirals push chips down and leave a cleaner top edge but clear chips less well. Compression bits combine both and suit laminated panels. The terms tearout and chatter, covered in the glossary on tearout, are worth learning, because the right bit geometry is often the fix.
Cutting diameter and multiple passes
Large profile bits remove a lot of material. Taking the cut in several shallower passes puts less strain on the router and gives a cleaner result. If a bit is tall or wide, a router table is often safer than hand-holding the router. Matching bit size to your machine matters more than bit count.
Handling, storage and care
Wear eye and hearing protection, and a dust mask when routing. Unplug the router, or remove the battery on a cordless model, before changing bits. Insert the shank fully, then back it out a small distance, as the manual indicates, to avoid bottoming out in the collet. Tighten the collet nut firmly with the wrench, and never tighten it without a bit installed, which can damage the collet.
Store bits so the cutting edges do not knock together, in a tray with individual holes or in their original packaging. Clean pitch and resin buildup with an appropriate cleaner and a soft brush; resin makes the bit act dull and can cause burning. Gentle cleaning is often enough to restore performance before any need to sharpen arises. For wider guidance, see the notes on cleaning after use. Inspect each bit before use: discard or have it professionally serviced if it has bent, cracked or missing carbide.
Building your set over time
Buy a few bits that serve your first projects, learn how they behave on scrap, then add as needs arise. Consider the router first, the table second, and the bits third, since a poor router limits what any bit can do. Prices and offerings change, so compare current specifications rather than relying on a list that may be out of date.