The light-gap technique as a tool for measuring residual stresses in bandsaw blades

The relationship between residual stress distribution induced in bandsaw blades by cold rolling during tensioning and the transverse deflected shape obtained when the tensioned blade is bent over a given radius is studied. It is shown that the light-gap technique is not a reliable estimator of residual stresses since, while two transverse deflected shapes may be close to each other, the corresponding stress distributions may be far apart. The technique may be improved, within limits, by decreasing the tolerance with which a desired transverse deflected shape is approached during the tensioning process. A method for computing this tolerance is given.