Countersinking drill-bit sets

In one drilling motion, countersinking drill-bit sets bore a pilot hole, a countersink for the screw head, and, if you plunge a little deeper, a counterbore to accommodate a wood plug. We recommend these three sets for different users and applications.

8-piece set, no. 07J15.80, $109 (photo above)
800-871-8158; leevalley.com

Tapered pilot holes grip the entire length of traditional wood screws. But tapered bits must run at about 250 rpm to avoid burning, and they tend to clog. Lee Valley's bits cut fastest with less tear-out and clogging than other tapered sets we tested. This 8-piece set drills holes for #4–14 screws with ³⁄₈ " and ¹⁄₂ " counterbores.

5-piece carbide-tipped set, no. PS-500, $100
800-445-0077; amanatool.com
The only set we tested with durable carbide-tipped countersinks, they cut quickly, cleanly, and without chatter. The set comes with its own plug cutter to match the 10mm counterbore produced by each of the four bits sized for #8–14 production screws (though we wish they went down to #4). Amana also sells tapered versions of these bits for $25 apiece.

5-piece set, no. 82501, $25
612-381-1060; insty-bit.com
Nothing exotic here: just twist bits in steel cutters sized for #4–12 screws. In our tests, every piece in the set cut clean countersinks and ³⁄₈ " or ¹⁄₂ " counterbores in quick fashion. As a nice touch, the manufacturer stamps the countersinks with the size of the matching bit. The ¹⁄₄ " hex shanks make for quick in-and-out connection in any hex-chuck drill/driver.