What distinguishes these bits from others (like a straight bit used for rabbeting) is the addition of a circular pilot bearing at the bit’s tip that acts like a spinning wheel riding along the edge of the piece being cut, guiding the cutting arm to the perfect depth. As a result, the width of the cut is determined by the size of the bearing, with a smaller bearing producing a wider cut. The most common sizes of rabbet bits are 1¼ inches and 1⅜ inches, and most bits come with several interchangeable bearings ranging from ⅜-inch to 1⅛ inches. Is it because a trim router and a 1/4" bit would just find that too hard, even if I did multiple passes? In this episode of Getting Started in Woodworking, the forth in our series on building an oak bookcase, we demonstrate how to cut accurate dadoes and rabbets with a router and a simple jig. The above bits are fairly common in terms of use, most joinery workshops will have them, but there are some router bits that are only used for specific jobs, these are normally referred to as specialist bits.

The type of joint you choose will impact the finished look and the strength of the joint so consider where the cabinet or shelf will be installed and whether it will need to hold heavy duty or lightweight items. How to cut a rabbet in 4 steps Flush trim bits are essentially straight bits with a pilot bearing that’s the same diameter as the flutes. The bearing at the tip guides the cutting arm perfectly around the edge of a surface, allowing you to trim overhanging material perfectly flush. You can use this for shelf edging, veneer trimming, or to smoothly join edges. They’re also great for duplicating curved patterns from a template. For trimming purposes, these bits can be used in a hand-held router, but a table-mounted router is best used when replicating patterns with a template.

Bearings give bits versatility

Very similar to a chamfer cutting bit, the rounding over router bit is generally used to round off sharp and acute edges to leave a nice smooth and rounded one.

What I actually did as a test was to make multiple passes across the table saw blade at a height I thought was right for the extra 6mm or so... this didn't leave something as neat as I wanted and I needed to clean up with a chisel. Next time (this weekend) I'll probably try the 2 cuts on the table saw method. If you don’t already own a router, now is the time to buy one. These versatile power tools are capable of a wide variety of tasks, and can often accomplish tasks in place of a tablesaw. They are ideal for cutting dadoes and rabbets, particularly when paired with the simple t-square jig detailed in this episode. One other very handy cut the straight cut bit can make is a plunge cut. This is when the bit is lowered down on to the surface and then starts to cut down in to it. The worst base for this sort of work is actually the standard fixed base, which has a very small footprint and only takes Makita's own guide bush (which is 9.5 or 10mm from memory, AFAIK no other sizes available). It isn't difficult to make a larger (more stable) sub base from acrylic plastic (Perspex, Lucite, etc) or polycarbonate (Lexan, etc), in any shape you like, such as an egg shape with an offset handle. A better base for your purposes is the plunge base, which can be set up to allow repeatable depth cuts. It is more stable, too, because it has a bigger footprint than the fixed base, and has the advantage of being able to take Porter-Cable guide bushes when used with a commonly available adaptor. That gives you the ability to do template routing with a selection of guide bushes. The plunge base can also be used with the same micro adjustable side fence that is sold for the Makita RP1110 router (and is compatible with other fences from Bosch and DW) Straight bits are perhaps the most frequently used type of router bit since they can be used in a wide variety of applications. While in a class of their own, straight bits are usually used for cutting different types of square-shaped grooves. These grooves can be cut with the wood grain (the technical definition of a “groove”), against the wood grain (called a “dado”), or along the edge of wood to produce an L-shaped shoulder or “rabbet”. All of these cuts are often used for joining two pieces of material. For example, the mortise and tenon joint is a very popular and sturdy joining technique that can be easily made with a straight bit. Aside from joinery, straight bits can also be used for mortising in door hardware, or for grooving a channel where a decorative inlay can be inserted. They can even be used in place of more specialized bits (like rabetting, described below), which contributes to their impressive versatility.As they effectively cut a 45° bevel edge, they are also commonly used to ‘bevel” the edges of two adjoining surfaces to create a mitre joint so that they meet to form a right angle. More often than not, these are generally shaping or moulding bits that are used to create specialist moulding’s and shapes, sometimes two in a single pass. The purpose of the bearing is to allow you to easily guide your router bit along a piece of work so that your (normally) shaping or detailing work is kept straight and accurate. A rabbet joint is stronger than a typical butt joint—which is simply two straight edges joined together—because a rabbet provides more of a mechanical connection. Cutting the rabbet creates more surface area where the wood can be glued and therefore creates a stronger joint than simply nailing or gluing together two straight edges. For an even stronger rabbet joint, opt for a double rabbet joint where rabbets are cut into both edges of the adjoining workpieces. Rabbet joints vs. dado joints Essentially the shank is the part of the bit that your router collet grips on to so that when the motor is running it allows the bit to rotate and do its work. Generally, router bit shanks are available in two different sizes; 1/4 inch and 1/2 inch.

The straight cutting router bit is arguably the most commonly used type of router bit. As the name suggests it’s used for cutting straight cuts with a flat base e.g. the channels at the side of drawers that the drawer bottom sits in and certain timber joints such as a lapped joint. For the router-table method to be both safe and successful, you must use the proper bit. Although a rabbeting bit seems logical, most are not designed for this application. On most rabbeting bits, the carbide cutter extends proud only on the top and has relief angles ground in the carbide to reduce burning. The bottom of the bit is often an afterthought, with the main body sometimes extending below the actual cutter. Some have a shear cut which, although beneficial when cutting from below, impedes the cut if used above since it directs chips to the base of the cut, which is exactly where you don’t want them to be. Also, many rabbeting bits do not have a long enough shank for the cutter to get to the proper height without seriously compromising how much of the bit is in the collet. Use slot-cutting bits If you are fairly keen on carpentry and joinery, the router is one of the best power tools you can have in your tools arsenal as it can be used for a huge variety of jobs from cutting hinge recesses, mitering worktops, trimming and shaping edges to cutting a whole variety of timber joints. They’re available in cut diameters ranging from 3/16-inch to 1½ inches and have either one or two ‘flutes’ (cutting arms) depending on how large or fine of a cut you need.The majority of router bits that feature a bearing normally also include bearings of different sizes with the bit or in the kit. As the bearing follows the object your are working on, the size of bearing dictates the depth of the cut, so for a different depth of cut you can simply change the bearing for a different size. You’ll find rabbet joints most often in cabinets, drawers and shelving, but there are many other uses for rabbets in general construction. Woodworkers like them because they are: There are several different parts that make up a router bit and understanding each of these and what they do is integral to they’re use. The main router bit parts to note are the shank, the body, the cutting edge and if it has one the bearing guide.