While a dado blade is a handy tool for cutting dadoes and grooves, it takes a bit of setup to get the exact width you need. If you just want to slap in a blade and go, Amana Tool’s Carbide Tipped Groovers are for you.
Made to cut 1/4″ grooves (and only 1/4″ grooves), Amana’s fixed-width groover cuts a kerf exactly 0.250″ wide. It comes in both 8″ and 10″ diameters for saws with a 5/8″ arbor. Their adjustable groover can cut three different sized grooves: 5.5 mm (1/4″ undersized plywood), 1/4″, or 5.9 mm (1/4″ veneered plywood), depending on where you locate removable carbide cutters. They sell two versions of this 8″ blade — one for 5/8″ arbors and one for 1″ arbors.
The fixed width 8″ groover runs $170 and the fixed width 10″ groover runs $190. If you’re interested in the adjustable groover, it’ll cost you double, $340.