1/4 Router Bits Buying Guide
If you've ever shopped for router bits, you've probably noticed that they come in a huge variety of types and sizes. This is a good thing because it's the variety of bits that makes routers such versatile tools. If you look closely, you'll also find that router bits fall into two categories, those with 1/4-inch shanks and those with 1/2-inch shanks.
Most bit types are available in both shank sizes, and most router kits come with collets to fit both sizes of a shank. If you can use either size, you probably wonder which is better. The short answer is: All things being equal, 1/2-inch is better. There are some cases where 1/4-inch is the only option and many cases where shank size simply doesn't matter.
Router Bit Shanks
The router bit shank is the solid, cylindrical part of a router bit. It's the part of the bit that goes into the collet of the router. There are two common sizes of router bit shanks: 1/4" and 1/2". Many routers come with interchangeable 1/4" and 1/2" collets so that either size bit can be used, but some accept only 1/4" shank bits. Whenever possible, use bits with 1/2" shanks. They provide better stability with less vibration, and they typically produce a smoother cut and have longer cutter life. Except for very small and very large profiles, router bits typically are available in both shank diameters.
When 1/4-Inch Bits Make Sense
The advantages of 1/2-inch-shank bits don't always apply (or they are negligible), and sometimes 1/2-inch shanks aren't even available. As a result, most woodworkers who use routers end up with a collection of bits containing both 1/2-inch and 1/4-inch shanks.
One potential advantage of 1/4-inch bits is that they can be less expensive. With router bits, you certainly get what you pay for, but if you need a bit for a specific project and might not use the bit much otherwise, an inexpensive 1/4-inch bit might be the best option. Availability is another potential advantage of 1/4-inch bits, as some stores carry a wider range of 1/4-inch bits than 1/2-inch.
Finally, if you have a small router or a laminate router, the tool may accept only 1/4-inch bits, in which case the question of shank size is moot. But even if your router can accept both 1/2-inch and 1/4-inch bits, and the bit you need isn't large or particularly long, you'll probably get similar performance with either shank size.
Will You Be Mounting Your Router Or Making Handheld Cuts?
Some bits can be safely operated only in a table-mounted router with a variable-speed feature. So, for example, if you want to make a cabinet with frame-and-panel construction, you’ll need to get or build a router table before you can safely use the stile-and-rail bits and panel-raising bits required for such a project.