Wear and failure of high-speed steel bimetal bandsaws when cutting ball-bearing steel

This paper reports experimental data on the wear and failure modes of high-speed steel bimetal handsaw blades cutting annealed ball-bearing steel circular bars. Several different methods of assessing the wear modes and mechanisms are evaluated; Cutting and thrust force components, Set width, "Out-of-square" cutting, Wear land area and geometry,; and, Surface characteristics of cut-off workpieces. The failure mode established in the current work when bandsawing ball-bearing steel with a bimetal blade is "out-of-square cutting". There is a linear increase in the thrust force component as the bandsaw teeth wear, whereas the cutting force component experiences a non-linear increase. The out-of-square failure mode appears to be caused by unbalanced corner wear to the set teeth. The corner wear also influences the total set width and the quality of cut surfaces. The out-of-square failure mode occurred before the thrust force and wear land area reached the tertiary stage of wear. This work should be of great interest to the production engineer associated with cutting-off processes.