What dovetail router cutter

sizes are available?

Dovetail router cutters are most often sized according to the following dimensions:

Shank diameter of dovetail router cutters

The shank diameter is measured across the centre of the shank from any point on its circumference. 

Dovetail cutters are available with ¼" (6.35mm), 8mm (5/16"), ⅜" (9.5mm), ½" (12.7mm) and 12mm (½" approx.)  shank diameters. 

Overall length of dovetail router cutters

The overall length of a cutter is measured from the top of the shank to the bottom of the cutting edges or guide (if there is one).

Dovetail cutters range in length from 52mm (2" approx.) to 80mm (3¼" approx.)

Diameter of dovetail router cutters

The diameter is the maximum width of the path made by a router cutter in one pass, and is measured from the outermost point of the cutting edges through the centre of the bit. 

Dovetail router cutters have cutting diameters ranging from 6mm (15/64") to 25.4mm (1"). For wider dovetails, select a cutter with a larger cutting diameter and vice versa.

Cutting edges of dovetail router cutters

Length

This is the maximum length of the full cutting edge of the router cutter. It is measured from the top of the cutting edge to the bottom. 

Dovetail cutting edge lengths range from 6.35mm (¼") to 32mm (1¼" approx.)

Angle

This is the angle of the cutting edges in relation to the horizontal plane. Dovetail cutters have angles ranging from 95 degrees to 110 degrees. 

The larger the angle, the more pronounced the dovetail will be, and vice versa.

What size dovetail cutter should you choose?

For many applications, the size of the dovetail cutter will be down to personal preference; however, there are a few things you should bear in mind while selecting:

A greater angle doesn't equal greater strength

Despite what many people say, the strength of a dovetail joint is not affected by the angle of the dovetail. There have even been experiments carried out to prove this!

Ensure it suits the project

Dovetail cutters that produce smaller angles are often chosen when a more "subtle" look is preferred, while larger cutters, and therefore, dovetails, are favoured when users want to ensure their craftsmanship stands out. 

Match the cutter to the material

Generally speaking, larger dovetails will be needed to join thicker pieces of material, just as smaller dovetails will be much better suited to thinner, more delicate materials. 

Cutter size may be specified

For some applications, such as when using a dovetail jig, a cutter of a certain size must be used, so check the specifications for your particular project.