Bar and Billet Gauging—A Review

Abstract

Rod and bar has been rolled for many years without the benefit of any form of gauging beyond the holding of a piece of wood against the moving stock. Quality control at present depends on retrieving processed material after cooling and using micrometer measurements to make mill adjustments. Valuable time is lost before any alteration in mill parameters is revealed and setting up is time consuming without rapid feedback of rolled diameter. Furthermore, any form of gauge control is not possible without the rapid determination of the diameter and profile of rolled material. The driving force behind automatic control of rod and bar mills and the considerable loss of revenue incurred by wastage of stock and in setting-up time has driven many investigators to examine ways and means of measuring rod and bar diameters. Over the past two years many schemes have been evaluated and some instruments will be commercially available shortly. This paper seeks to review the more interesting developments that have taken place in this area over the past two years.