David Ashinghurst takes a look at screw drilling and driving systems that are designed to drill a pilot hole and countersink or counterbore in one stroke. These drills also have driver bits. Here, he compares prices, operation, counterbore sizes, and pros and cons for each. He evaluated the Chuck-Mate, the Insty-Bit, and the Snap-lock, and says that for general construction or paint-grade work, any of them work well and save time. And they help cut down on stray extension cords around your feet.

From Fine Woodworking #131