The commonly recommended method for stopping a drill bit at a marked depth is to wrap it with tape. While this works most of the time, the tape can slip, and if it doesn’t it winds up looking pretty ragged by the time you’re done with the fourth hole. I’m tempted to try one of these adjustable bit stops if for no other reason than its tape-goo-free operation — I’m a cheapskate at heart, but the only thing I hate more than spending cash is cleaning tools.
The stop, which also functions as a bump stop, wraps around standard 1/16″ to 1/2″ drill bits and holds tight to the bit with a quick twist. Constructed from nylon plastic, the drill stop will run you $6 from Woodcraft.