A clamp drill, or drill clamp, is a mechanical device that attaches to a portable drill and allows it to be used as a stationary tool. The clamps are most often used by trade professionals to allow a portable drill to be used as a bench grinder or buffer. Carpenters, plumbers, and mechanics often use clamp drills when working in the field — away from their shops or primary places of business. Clamp drills are more convenient for field work than a tool such as a drill press, and they can act as a replacement for a drill press, buffer or jig. Hobbyists also employ these tools when space in a workroom is limited and a larger standing drill press or grinder is not possible.
The primary purpose of a clamp drill is to lock a portable drill into place and keep it from moving while in it is in use. A carpenter, for instance, may use a drill clamp to cut holes for door knobs and deadbolt locks in conjunction with a hole saw bit. The clamp ensures all the openings cut will be consistent on every door. The ability to lock the drill in a single position attached to the work surface makes this tool useful to trade professionals.
A mechanic may use a clamp drill to lock a drill with an attached grinding wheel to a portable work bench. When precision is necessary, the mechanic may also turn to the clamp drill, allowing use of both hands to hold a part. A plumber may use the tool in a similar way, setting up a clamp drill with a buffing wheel attached. The plumber would be able to work with both hands safely and securely controlling the material being buffed. The portability and convenience make these tools part of most professional tool boxes.
While many pros use clamp drills, clamp drills are not limited to use by professional tradespeople. The imagination and ingenuity of the user is the determining factor in a clamp drill's usability. While not as popular as a circular saw or hammer, drill clamps are found in many toolboxes. When purchasing one of these tools, the determining factor should be the drill you are going to use it with. A clamp drill needs to fit properly to clamp onto the portable drill properly, so look for one that will fit your drill and the workbench surface to which it is mounted.