Abstract

The separation of bench marks and jaws have been used to calculate the elongation at break of two leathers using the 1957 SLTC specimen shape and the current IUP/6 large specimen. Two tensometers were used, an Instron and a 250 kg Howden. The jaw design is crucial if jaw separation measurements are used. Positive clamping is essential and self-tightening jaws should be avoided. The IUP/6 specimen gave lower but more reproducible values than the 1957 SLTC specimen. Jaw separation measurements were more reproducible than those from bench marks. In a separate experiment the three IUP/6 specimens, a modified version of the medium-size specimen and the 1957 SLTC specimen were compared. Seventeen leathers were tested using the Instron only. The results from the 1957 SLTC specimen by bench mark separation are very close to those obtained from the medium and small IUP/6 specimens by jaw separation. The large IUP/6 specimen gave lower but more reproducible values than any other specimen. The 1957 SLTC specimen gave worst reproducibility.