Precision Countersink. Because the Smart-Bit predrilling and countersinking tool is designed to perfectly match the shape, head diameter, and head angle of popular screws used for deck building and woodworking, it won't produce mushrooming when used with composites, says the maker. A stop collar that spins free of the bit protects the workpiece. The tool comes in sizes to fit #7 and #8 trim screws and #10, #12, and #14 flat-head screws. Packages include three drill bits and a hex wrench and cost $18 to $25. Starborn Industries, 800/596-7747, starbornindustries.com