A brittle-like crack propagation caused failure in a rubber office-chair roller. A crack initiated from the inside of the roller and propagated in a discontinuous brittle-like fashion, as indicated from the evolution of concentric fracture striations. Compressive fatigue was a dominant mode of loading. Nevertheless, the fracture surface of the failure-causing crack suggested a tensile-stress component was involved in driving failure.
Fasteners, made in high-production progressive dies from 0.7 mm thick cold-rolled 1060 steel, were used to secure plastic fabric or webbing to the aluminum framework of outdoor furniture. It was found that approximately 30% of the fasteners...