Abstract

For any one leather, the tearing load decreases as the thickness decreases, but not simply in proportion to it. For many leathers, the caring load y of grain splits is related to thickness x approximately by the quadratic equation y=k’ x if this equation were true for all leathers of any one type, the value of k’ would indicate whether a sample was strong or weak for its type and thickness. Unfortunately, however, there are leathers for which the above equation is not even approximately true, and, for these, values of k’ might be quite misleading. For this reason, it is probably better to assume a linear equation instead, and write yk (,v—A) where A is chosen as typical for the kind of leather under test; the value of k for any sample then indicates whether it is strong or weak for its type and thickness. For samples from the Official Sampling Position of chrome tanned sides, the value of A may be taken as 03 mm. For shoulder leathers (vegetable or. semichrome) its value appears to be about 08 mm.