Cut perfect rabbets with a router bit
Virtually every cabinet you build uses rabbet joinery somewhere: for lock-rabbet drawers, on inset doors, as a recess to house the back of a bookcase, or to rest glass in a door. A rabbeting router bit helps you make them all, and cuts rascally rabbets on curved edges, such as an arch-topped door—something not possible with a tablesaw.
Bearings give bits versatility
Rabbeting bits typically come in one of two diameters—1 1⁄4 " or 13⁄8 "—and can be purchased alone or with a set of replaceable bearings that alter the cutting width of the bit.
Quick Tip! Check the spin of the bearing before using a rabbeting bit. Some bits use stepped washers between the bearing and bit, as shown below , and if installed upside down, will keep the bearing from spinning.
The chart, below, shows the rabbet that results from using various bearings with a 13⁄8 "-diameter rabbeting bit. If you have a different diameter bit—or bearing—you can easily calculate the resulting rabbet.
To determine the width of your rabbet with a specific bearing, subtract the bearing’s diameter from that of the bit; then divide that result by two. Or, to determine which bearing to use for a specific rabbet size, simply multiply the rabbet width by two; then subtract the result from the bit diameter.
Rabbeting bits hog out large amounts of material, so minimize tear-out by making several light passes rather than a single deep one. Begin your rabbet with the router set to take a 3⁄8 "-deep cut at full width, making increasingly deep passes. Also, the large diameter of a rabbeting bit requires a slower router speed—from 16,000 to 18,000 rpm—to perform at its best.