A screw box is a specialized wooden or metal block containing an internal V-shaped cutter, functioning much like a threading die for metal. A woodworker twists the box over a properly sized wooden dowel to carve continuous external threads. It is typically paired with a matching wood tap to create threaded wooden joints for vises, clamps, and knockdown furniture.
Heard on the job
Soak that dowel in linseed oil for a few minutes before running it through the screw box to get cleaner threads.
Also heard as
- wood threader