Metallics BHDM3 Bell Hanger Drill Bit Dia 3/8" 13" Carb tip Fish Hole (1pc)

The BHDM3 is a 3/8 inch diameter bell hanger bit with an overall length of 13 inches, so it drills a 3/8 inch hole and reaches through stud bays, sill plates, and header framing that a standard-length bit cannot cross in one pass.

The fish hole is the eye drilled through the tip end of the BHDM3. After you bore through the framing, you feed wire or a pull string through that hole and back the bit out, dragging the wire with it. That saves going back with a fish tape on a blind bore, which is why electricians and low voltage installers use this style of bit for retrofit wire pulls.

The BHDM3 has a carbide tip, which is the reason to pick it over a plain steel bell hanger bit. Carbide holds an edge through the abrasive material a remodeler hits on old buildings, plaster keys, embedded nails, and the odd hit of block or brick at a sill, where a high speed steel bit rounds over.

A 3/8 inch bore suits single low voltage runs, coax, alarm and thermostat wire, and light cable pulls. For a bundle of romex or several cables through one hole you want a larger diameter bell hanger bit, since the 3/8 inch hole the BHDM3 cuts will not pass them comfortably.

It ships as one bit, packed in a pouch. If you want more than one diameter for mixed-gauge wire and cable pulls, you order each size separately rather than buying a kit.