请前辈帮忙翻译 a round-off conversion of 25mm per in ...? 嗯。echo关于换算率要四舍五入的说法更准确。 for pipe diameters a round-off conversion of 25mm per inch may be used, for example a 4 inch pipe may be referred to as a 100nd pipe. 可采用1英寸相当于25毫米这样四舍五入的换算率来换算管径的单位,比如说4英寸的管子就可叫成毫米公称直径为100nd的管子。查看更多