No German unit of weight is ten times the previous unit. The practice of reducing metric weights to customary sizes extends to volumes of liquid. Having converted to the metric system, Europe is returning to the very use of fractions which the metric system is supposed to eliminate, and giving these fractions new identities based on traditional human-scale systems. The inch is another customary unit that is retained in Europe. In Swedish tool shops, equipment is specified in tums , and in Norway, tommes , alongside metric.
Swedes also describe the sizes of electronic wafer boards in tums.
Inches are often used on the continent for plumbing. Whereas British plumbers converted to metric some years ago, necessitating the use of adaptors where metric pipes do not fit existing installations, in Belgium all plumbing equipment, whether fittings or pipes, continues to be supplied in customary measures. Germans also use inches for producing firearms, as illustrated by .202 and .303 rifles. Most, if not all, European publishers use the inch for measuring type size and ink density because global computer and printer technology is now inch-based. Shipping and aviation are two areas where customary units are used frequently.