These liner drill bushings (L) don't have a head, so they can be placed closer together than headed liner drill bushings. Type L liner drill bushings are permanently installed in a drilling jig to allow renewable slip-fixed (SF) drill bushings to be inserted into the jig and to ease replacement of the drill bushings when they become worn or damaged during metalworking tasks. Liner drill bushings ensure accurate placement of type SF drill bushings and protect the jig from wear and damage when replacing the drill bushings.