Router Bits

Do they have you confused?

When thinking about router bits do you get confused, wondering what bit you should use for what job, what speed should my router run to ensure the best cut, and how should I care for my bits?  My hope is that I can shed a little light on the subject for you.

The Parts

First of all router bits are made up of some basic parts some of which are common among all the bits and some parts that are unique to it's type of bit.

        Shank - the shanks come in 2 basic sizes, 1/4" and 1/2".  The 1/2" bits can be classified heavy duty bits, and are the suggested size bit you should purchase.  There are varying opinions on why the 1/2" is a better option.  But if you think in a logical manner your 1/4" bit being smaller in size will heat up faster.  A hot router bit can cause burning in the piece you are working, which can be a pain to correct.  Of course metal when heated becomes weaker, which can cause distortion, a distorted bit means that is does not cut as accurately.  A hot bit means that cutting edge can dull quicker.

        Cutting Edge - of course the cutting edge is the business part of any router bit, the part that cuts and removes the wood you want removed.  The cutting edge comes in varying sizes and shapes.  Most bits today come with a carbide cutting edge.  You can find high speed steel bits.  Carbide bits perform much better than the high speed steel bits.

        Pilot - The Pilot guides the router along the piece you are cutting.  The pilot can be an extension of the shank or be a ball bearing which is held in place using a screw which is sometimes referred to as a cap screw.

Sizing Bits

        All bits have a specific size, but that size can refer to different areas of the bit.  For example the size may refer to the length, diameter or the radius cutting areas of the bit.  This depends on the type of bit such as a 3/4" round over bit.  The 3/4" refers to the radius of the cutting area.  In other words the bit will create a 3/4" round over.  A 3/4" straight bit refers to the diameter of the bit, it will remove 3/4" of material at varying depths.

Router Speeds

        As a rule of thumb the larger the bit the slower it should move.  The following are guidelines that freud (freud is a registered trade mark).

Router Bit Care

To ensure a long life of your router bits there are some basic things that you want to do.  First when using your bits cut small amounts of material at a time, this will help prevent you overheating the router bit and not only extend the life of the bit, but it will extend the routers life as well because you won't be overloading it.  You will also want to use the shortest and largest bit you can.  This will help prevent chattering and that dreaded enemy of the router bit heat.  Keep your bits clean and free of pitch.  Pitch dulls your cutting edge and also causes unneeded heat.  You can buy special cleaners to clean your bits.  If your bit has a ball bearing guide ensure that it moves freely and keep them clean as well.  If you find that the bearings are starting to stick and cleaning and lubricating does not free it up then you will want to replace the bearings and or guide.  Now of course sharp bits perform the best and caring for the bits will extend their life.  Good quality bits can be sharpened.  If you elect to sharpen your bit's I strongly suggest that you do not do it yourself , but have it sharpened professionally.

The Types

Router bits can be grouped into 4 basic groups.  Some bits can fit into more than one group.

Edge Bits - These bits tend to have a guide that rides along the edge of the piece being milled and creates a profile of some type.  Such as a Chamfering, Flush, Beading and Round - Over bits.

Grooving Bits - These bits do just as the name suggest, they create a grove into the piece being milled.  These bits tend to be used in conjunction with a straight edge or a template.  Of course you can free hand if you desire, but I know I am not that good.  The type of bits that can be included in this group are Round-Nose, V-Groove and Straight bits.

Joinery Bits - These bits are used to create joints of different types, such as, Dovetail, Drawer Lock, Finger Joint, Tongue and Groove, and Rail and Stile bits.

Specialty Bits - These bits may or may not fit onto the other categories.  These bits include the Raised Panel, Vertical Raised Panel, Key Hole, and T-Slot bits.