Normal angle for a dovetail bit?

[Mark Kelly]

Is there a normal or regular angle for the dovetail bit? On a new project coming up, I need a 1/2" dovetail bit and when I went to buy one, there were all sorts of angles to be had from 7 degrees to 18. Is one angle better than the other?

[Alan Turner]

If you are using a regular dovetail jig, you might want to follow the instructions. Other than that, it depends on the application. Normally, if there is such a thing, 1:6 for softwoods; 1:8 for hardwoods, is the common belief. These translate to 14 deg and 9 deg. For dovetailing a drawer rail into a carcase side, 14 degrees is what I use.
Tell us more about your usage, and we may be able to help a bit more.
Alan

[Mark Kelly]

Actually, It is for a joint that was in a woodsmith magazine in building a table lamp. However, I don't like to buy something unless I plan on using it for other stuff (a.k. drawers!) Since I cut all my dovetails via hand or bandsaw (I don't have a jig...actually I would like to make on rather than buy one) I never looked at dovetail bits. However, now that I need one, I was asking so that I could learn what the different angles were for.

There should be no reason why a 14 degree dovetail would work on hardwood, correct?

[Alan Turner]

14 deg. will work. Just recall that the steeper the angle, the more short grain, i.e. weakness, you have, esp. at the points. The reason that the softwoods use a 14 deg. DT is that the wood is so soft that it will compress, and the joint will loosen. I too cut all of my DT drawers by hand. But I use a router for the drawer rails in carcase work. I rarely work in softwood, but occassionally I work in heart pine, if the piece needs that sort of look.

In terms of a jig, the Charlesworth books discuss a bandsaw jig, which I made, for both 1:8 and 1:6, and it works really well for those very heavy, thick DT's, like you might see on a Klaus bench. The pins are cut with an angled sled, like you might use on a drill press, and the tails are cut with that same angle between the stock and the fence. Pretty simple to build; just be sure that all of your angles are identical!
Alan