MEASUREMENT OF BENDING STRENGTH USING SPECIMENS CUT FROM COMMERCIALLYPRODUCED HIGH-STRENGTH PORCELAINS

To estimate the strength of commercially produced porcelains, specimen s must be cut from the commercial products, In this study, the effects of sample preparation processes, such as cutting or grinding, and mea suring methods on the bending strength and its distribution were inves tigated for the specimens cut from commercial products, and compared w ith those of slip-cast specimens, The bending strength of specimens cu t from traditional porcelains, which is smaller than 150 MPa, agreed w ell with that of slip-cast specimens irrespective of sample preparatio n method, On the other hand, in the case of high-strength glazed porce lain products, which show values larger than 250 MPa, the bending stre ngth was estimated accurately by eliminating the chipping in glaze or cracks in the body by means of grinding away over 150 mu m on one side with a #400 diamond wheel, and agreed well with that of slip-cast spe cimens.