the size listed on the bin or whatever size the sheet or board says it is. THEY LIE !!!! It's pretty common knowledge now that your work pieces don't always live up to their description. On the other hand, your router bits, rub collars, bearings usually are dead on their descriptive dimension. Since many times a board that needs dados is too long to be comfortably machined on a table saw the go to machine tool to complete the dado is the router. How do you reconcile the "almost, nearly, just about "size of the stock to fit the dado with the exact sizes of your router set up? Here is a super simple easy to build inexpensive idea for a jig that will match the socket to the stock every time accurately without fail (with the possible exception of operator error
).
http://www.woodmagazine.com/woodworking ... h-dado-jigThen again for the purists among us there is always the direct marking out with a knife, kerfing with a back saw, and a chisel and mallet followed with a router plane to smooth things out all to the quiet hiss of a blade into wood and the tap tap of the mallet. Same cat different skin