Imperial preference

Eventually, ancient rules of thumb gave way to more carefully defined units. The metric system was adopted in France in 1799 and the British Imperial System of units was established in 1824. In 1893, the English units used in the United States were redefined in terms of their metric equivalents the yard was defined as 0.9144 meter, and so on. But English units continue to be used in the United States to this day, even though the Omnibus Trade and Competitiveness Act of 1988 stated that it is the declared policy of the United States...to designate the metric system of measurement as the preferred system of weights and measures for United States trade and commerce. ... 

The ASTM test follows the same principles but differs in certain details. The standard test specimen is based on imperial units, so that the preferred test piece is 127 mm long by 12.7 mm wide by a thickness of 12.7. 6.4, or 3.2 mm. The details of the apparatus used are the same as for the Izod test, which is covered in the nc.xi section but the form of expressing the result is different, being based on the energy normalized with respect to the length of the notch only, and not on the area behind the notch. This only serves to add to the difficulty in making comparisons between data obtained by the ASTM standard, with its dilTcrcnt test piece sizes and impact conditions, to that of the ISO standard. 

My father bowed slightly and said Imperial Majesty, I am very flattered. But I would prefer something which I could hand down to my children. ... 

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