Yet another adaptation of a straight bit, a rabbeting bit sports the same cutting edges but places them on a shorter, wider body. The top-mounted bearing rides the workpiece, while the cutting edges create the rabbet. The diameter of the bit combined with the depth of cut determines the size of the rabbet.
Rabbeting bits can be purchased in a variety of sizes depending on your joinery needs, but there is a one-size-fits-all version that uses a single bit with interchangeable bearings. Although the bit diameter doesn’t change, the different size bearings alter how much of the cutter length is exposed to the edge of the workpiece. Typically, these adjustable rabbeting bits come in a set with bearings that will create rabbets from 1/8" in width using the largest bearing, to 1/2" wide with the smallest. The number of bearings included varies with manufacturer, and some sets even include a bearing that exactly matches the overall diameter of the cutting edges, which can effectively turn the rabbeting bit into, you guessed it, a flush-trim bit.