Auger Bits

Auger Bits

An auger bit bores deep clean holes through timber and works quite differently to a twist drill. A screw-threaded point at the tip bites into the wood and pulls the bit forward, so it feeds itself rather than needing you to push, and a single deep spiral flute lifts the waste continuously up and out of the hole instead of packing it in. That is what allows an auger to go far deeper than a standard bit without binding or burning, which is why it is the bit for joists, beams, fence posts, sleepers and running cable or pipe through structural timber. Two figures describe it: diameter sets the hole size, so match it to whatever passes through rather than guessing, and length sets the maximum depth. A mini auger is a shorter version for the same job in thinner sections, and it is easier to control and less likely to wander. Practical points that matter with augers more than other bits. Run the drill slowly and let the screw point do the pulling, because forcing it will stall the drill or split the timber. Hold the drill firmly, since an auger grabbing in hardwood can twist the tool sharply out of your hands. And back it out periodically on very deep holes to clear the flute. Augers are for timber only and will be ruined by nails, masonry or metal.

Dargan supplies a mini auger bit at 25mm by 100mm. For twist and masonry bits see Drill Bits, for larger diameters Hole Saws, and for the wider range Power Tool Accessories.