Installer drill bits and self-feed bits are the workhorses that let plumbers and electricians run wire and pipe through framing quickly and cleanly. Knowing which bit suits which task saves real time on the job.
What Makes an Installer Bit Special
Installer bits, sometimes called bellhanger bits, are extra long and have a small hole through the tip. After drilling through a wall or stud, you thread wire or fish tape through that hole and pull the bit back out, drawing the wire with it in one motion. The extra length reaches through multiple studs, floors, or wall cavities that a standard bit could never span.
Self-Feed and Auger Bits for Bigger Holes
When you need to bore larger holes for cable bundles, conduit, or plumbing runs, self-feed bits and wood auger bits take over. A threaded screw point pulls the bit into the wood, so you supply guidance rather than heavy pressure. Auger bits clear chips efficiently through their spiral flutes, keeping holes clean through thick joists and studs.
Choosing the Right Bit for the Trade
- Fishing wire through walls: A long installer or bellhanger bit with a wire hole.
- Cable and conduit runs: Self-feed bits size the hole in one pass.
- Deep boring through joists: Wood auger bits pull through and clear chips.
- Reaching between floors: Extra-length bits span the distance safely.
Tips for Trade Drilling
Know what is behind the wall before you drill, and be mindful of hidden wiring and plumbing. Keep the drill square so the bit exits where you expect, run auger and self-feed bits at a lower speed for control, and back off if the bit binds. Sharp, American-made bits pull straighter and resist the heat that dulls cheaper tools on long runs. For electricians specifically, our electrician drill bit guide breaks down the best options.
Durability Pays Off
Trade bits take abuse, so quality matters. A well-made auger or installer bit stays sharp through countless holes, keeps its screw point true, and resists bending under load, which means fewer replacements and less downtime.