Router bits are designed to serve three primary functions: To create wood joints, to plunge into the center of a piece for grooves or inlays, and to shape the edges of wood.
When you're shopping for individual router bits or router bit sets you'll mainly see two different types: carbide-tipped bits and hardened steel (HSS) bits. Solid carbide tipped router bits and tungsten bits may also be available.
Types of Router Bits
Providing straight and square-bottomed grooves, you can purchase this bit in a range of diameters but is most common in a ¾, ½, and ¼ inch sizes. With this bit, you can cut grooves, dadoes, and rabbets.
This is the correct bit when you want to shape an edge on a chair arm, tabletop, or shelf. Rounding over sharp edges, this bit is equipped with a ball-bearing pilot which will direct a cut’s width. You can change the cutting depth when you adjust the base of the router. These bits are available in a variety of sizes and are labeled by the cut’s radius. Most commonly, you will see rounding-over bits in 3/8 and ¼ inch sizes.
One of the more popular bits that shapes edges, the Roman ogee bit cuts classic decorative detailing with its distinctive profile into an edge of a horizontal rail, vertical stile, picture frame, and tabletop. With a ball-bearing pilot fixed to the bit’s end, you can control the cut’s width. Most commonly, Roman ogee bits are found in 3/8 inch, ¼, and 5/32 inch sizes with the 1/4-inch bit able to serve most of your needs.
Creating a basic L-shaped notch cut on a board or panel edge, a rabbeting bit allows you to form a rabbet joint. Using a rabbeting bit is one of the easiest ways to cut a rabbet. Designated by the depth and width of cut created, the most common bits are ½ and 3/8 inch bits. You will see rabbet joints most often when building drawers for cabinets, installing cabinet backs or joining cabinet sides to the cabinet top.
The Core Box Bit is one of the non-piloted router bits that are good for cutting round-bottomed grooves. Commonly used for routing flutes in vertical stiles and columns, this bit is handy when carving wood platters and plates or routing a decorative groove in a door panel. Available in diameters from 1 ½ to 1/8 inches, the most commons sizes used are 3/8 and ¼ inch diameter bits.
This bit can cut a decorative V-shaped groove in wall paneling, table legs, drawer faces, and cabinet doors. This is a non-piloted bit that is available in a wide range of V-groove angles and diameters with the ½ inch diameter bit with a ninety-degree cutting angle most commonly used bit.
Router Bits Signs of Quality
While you can’t assess some factors by eye – such as the hardness and quality of the carbide or the bit’s overall balance, there are things you can look for. 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. And 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.
Price can be an indicator of quality. The old saw applies: In general, you get what you pay for. Here at Rockler, we offer our own line of router bits designed for the serious woodworker. Rockler bits are made with high-quality ISO K10 and K20 carbide and are sharpened with 600-800 diamond abrasives. They also are precision-balanced and geometrically designed for superior chip ejection (High quality router bits on konetool here).
How do I use router bits?
To use a router bit, you need to properly attach it to a router and work on the material and project that the bit is intended for to ensure the best results. Using a router requires precision and patience to adequately align the router and slowly feed it through the material, allowing the rotating router bit to operate at its optimal power.
Forcing the router through the material may get the cut done faster, but you risk snapping the router bit off due to excessive force, and you are likely to char the material and give it an uneven edge that will need to be sanded or smoothed. Instead, use shallow, slow passes to get the best cut, working your way deeper into the material with each pass.
How do I sharpen router bits?
To give your router bits the best edge to get the job done, you should take them to a professional sharpener. They will be able to maintain the proper cut and shape of the bit while returning it to like-new sharpness.
However, if you cannot take the bit to a sharpener, you can use diamond hones to remove a thin layer from the cutting blade’s two edges. Lubricate the diamond hone with water and lay the flat side of the bit against it. Stroke the bit back and forth across the hone, removing thin layers of the bit with each pass until the cutting edge is returned. To keep the bit balanced, be sure to stroke both sides of the bit an equal number of times.
How can I clean router bits?
Router bits can quickly become coated in resin when working with woods, like pine, that is naturally very resinous. You are also likely to get tar, dust, and other miscellaneous debris baked-on to the bits, interfering with the router’s operation and the finish on the wood.
Regular cleaning of the bits takes care of this issue. Begin by picking up a router bit and resin cleaner online or from your local hardware store. The solution should be properly prepared according to the manufacturer’s recommendations and then sprayed or brushed liberally all over the cutting edges of the router bits. Let the bit stand for 10 to 15 minutes with this coating, then proceed to scrub the bit clean with a toothbrush or brass wire brush under a stream of warm water. After washing, dry the bits properly and consider using oil to coat the bits and protect against corrosion.