Question

请各位英语高手赐教！

The last two digits give the nominal diameter B in eights of an inch and the digits preceding the last two give the nominal width W in thirty-seconds of an inch.
其中in eights of an inch和in thirty－seconds of an inch这种表达如何解释啊？谢啦

Answer 1

前二个数字给在一英寸的eights的有名无实的直径B，并且在最后二之前的数字在一英寸的三十秒钟给有名无实的宽度W。

Answer 2

in eights of an inch:在一英寸的eights
in thirty－seconds of an inch在一英寸的三十秒钟