Reconditioning small diameter holes - by burnishing with wire rotating at high speed

摘要

The internal surfaces of holes of small diameter, less than 5mm, are reconditioned by hard rubbing by an inserted wire, rotating at high speed, and sweeping along the hole. The hole is aligned with the wire holder, which is carried in a chuck. If it passes through a rotary support may be provided at the otherside. For blind holes, or where access to the rear is difficult, it is supported at one end only. Wires may be single or formed from twisted strands, with curved ends so that tips rub the surface. They may be helical or sinusoidal to increase rubbing area. The beneficial effects of shot or bead blasting in work hardening and smoothing metal surfaces are well known. These processes are suitable for use in large holes. The process described can be applied to produce similar benefits in holes of small diameter with extremely simple equipment.