Have you ever seen a big, ugly crack in the lid of a chest? Underneath, you'll probably find a few cleats running across the grain to hold the lid flat. Chances are the cleats' screws caused the crack by preventing the lid from shrinking and swelling with the seasons. It's a classic mistake. Two new 1/2-in shank carbide bits from CMT offer a quick way to deal with this wood-movement problem and many others, such as fastening a solid-wood tabletop to a base. In one operation, they allow you to plunge-cut a long, counterbored slot for screws to slide back and forth, which allows solid wood to shrink and swell without cracking. One bit is designed for #8 flat head screws, the other for #8 pan head screws, plus washers. The bits work in wood up to 1-in. thick.
CMT, cmtusa.com, (888) 268-2487, Flat Head Screw Slotting Bit, 813.601, $37; Washer Head Screw Slotting Bit, 813.701, $37.