Several thousands of new 16 mm diam alloy steel sling chains used for handling billets failed by chain-link fractures. No failures were found to have occurred before delivery of the new chains. It was observed that the links had broken at the weld. It was found that all failures had occurred in links having hardness values in the range of 375 to 444 HRB. It was revealed by the supplier that the previous hardness level of 302 to 375 HRB was increased to minimize wear which made the links were made notch sensitive and resulted in fractures that initiated...