When a distributor stocks chrome plated rod, one of the quietest but most consequential decisions is which chrome thickness to hold on the shelf. The two most common specifications in general hydraulic service are a nominal 20 µm and a nominal 30 µm of hard chrome. They look identical in the rack. T
A stockist in Rotterdam once opened a container of honed tube that had spent five weeks crossing from Asia, only to find a thin bloom of surface rust creeping along the bore of nearly a third of the lengths. The steel was correct, the tolerances were correct, and the mill certificates were in order.
A distributor once asked me why one of his customers, a crane builder, kept specifying hollow chrome plated rod when solid rod was cheaper and simpler to stock. He assumed the customer was overcomplicating things, but in fact the crane builder had good reasons: the hollow rod let him run hydraulic l