Q. I’ve started to work on laying out and cutting dovetail joints by hand, and I’m confused about the proper angle to use for dovetail joinery. What are the most common angles, and what are the factors that determine what angle to choose?
—Carl Minnick, via email
A. Professional woodworker Chris Hedges replies:
Dovetail angles are expressed in two ways: as ratios and degrees. 1:8 roughly translates to 70 and 1:6 translates roughly as 90. These days, we often hear that 90 is recommended for softwoods, while 70 should be used for hardwoods. The fact that router bits and dovetail gauges are made in these angles reinforces the notion that they are the preferred angles to use. But if you happen to study antique furniture, you’re likely to see dovetail angles that range from 7° to 140 (1:4 ratio). Woodworkers who came before us chose their dovetail angles for the sake of appearance, I suspect. This notion is reinforced by research done at the Forest Products Laboratory. FPL testing on dovetail joints made at different angles between 7.5° and 17.5° showed no difference in joint strength. My suggestion: Invest in a good-quality bevel gauge that allows you to choose your own dovetail angles, and train your eye to be your guide in deciding what angles to cut.
