Electric Routers are one of the most versatile tools in the woodworkers shop. What is the power behind this versatility? Simple, it’s all in the router bits.
Let me take a moment to caution woodworkers new to the router. It is a very powerful tool. The shaft spins very fast and can do some serious damage to you and your project if you are not careful. It also throws out a lot of wood chips some of which will be making a beeline for your eyes. Put on your safety glasses and hearing protection and pay attention to your work!
Router Bits: There is a seemingly endless variety of router bits for every imaginable woodworking task. Some bits are relatively small and inexpensive, other’s large and pricey. What should you look for in a router bit and how much should you pay? Read on and all will be revealed.
Collets: The first step is to match the router bit to the woodworking job and to the router. Router bits are secured to the router with a collet. These collets come in three sizes 1/4″, 3/8″ and 1/2″. Smaller routers may use only smaller collet sizes but larger routers will usually have more than one collet or collet adapters to allow you to choose the size you need.
Shanks: The shank is the smooth upper section of the router bit that enters the collet. There are three standard shank sizes, 1/4″, 3/8″ and 1/2″. The size of the shank is usually related to bit size. For instance a straight 1/4″ rabbiting bit usually has a 1/4″ shank which fits in the 1/4″ collet. A 3/4″ rabbiting bit will have a 3/8″ or 3/4″ shank which fits in the corresponding size collet.
My preference is to use larger shanks, 3/8″ or 1/2″ even for smaller router bits. Why? Well, there is a lot of torque on those bits as they enter the wood and a lot of heat buildup. I believe that a larger shank offer’s better support to the cutting edge, especially plowing through tough woods. In my experience those larger shafts translate to longer bit life.
Cutting Edges: Now let’s turn our attention to the cutting edge. Regardless of the task, each router bit has a very sharp cutting edge. These edges can be made of either carbide or high speed steel also known as” HSS.” Carbide is better and lasts longer than HSS but it is also more expensive.
I’ve said it before and I’ll say it again, buy the best you can afford! I have had to run out on occasion and buy a cheap router bit from the hardware store. I have always paid way more than they are worth. They don’t cut smoothly; they dull quickly and are much more likely to leave an ugly burn mark on your lovely woodworking project.
Bearings: Some router bits such as those for flush trimming, rounding over, slot cutting and edge forming come with bearings on the end. These bearings allow the bit to follow an edge or a guide limiting the depth of the cut. Some bearings are adjustable allowing you to change the depth of the cut. It is important to keep these lubricated and free of dust buildup so they don’t stick and cause burns.
Anti-Kickback Design: Many of today’s better made router bits have an anti-kickback design built into them. This is important because, as I noted above, routers are a high speed tool. Taking too much wood in one bite can cause the router bit to “grab,” and throw the wood back at you or cause the router to lurch forward and out of your control leaving you exposed to the spinning cutting edge. An anti-kickback router bit limits how much wood the bit can take in one bite. These bits usually have a painted body; blue, yellow, or red depending on the manufacturer. That makes them easier to spot but be sure to verify that it does in fact have this safety measure built in.
There are many excellent bit manufacturing companies out there. Be aware though that top quality bits are not usually sold at hardware or home stores. To get the best bits, at the best prices, shop around at dedicated woodworking stores in your area or search on-line. Several router makers have bit lines and there are a few companies that specialize in router bits. You’ll be amazed at the variety!