On the Measurement of Shore Hardness of Sheet Metals

Abstract

Although this is not the proper way of its application, the Shore scleroscope is often used for the commercial measurement of hardnesses of sheet metals because of its character. The present report discusses the influence of the hardness of the anvi1 of the scleroscope and the way of mounting of specimens on the measured va1ue of the hardness of a thin plate as well as the variation of the hardness number of a laminated specimen with its thickness. The results of this investigation are as follows : i) The hardness of a thin metallic specimen should be measured on a single sheet, unless the specimen is laminated to a certain thickness. ii) If the hardness is measured in the way mentioned above, the hardness value given by the instrument remains approximately constant independent of the hardness of the anvil, if the anvil is only harder than the specimen. iii) Thus the indicated value of the hardness of sheet metals may be influenced by the hardness of the anvil, but as it does not remarkably change with the variation of the hardness of the anvil, this value may be used for commercial purposes.