是1/3,参考《机械制图》国家标准截图:
是1/3
规范的线宽系列关系是:b,0.7b,0.5b,0.25b。b即最粗线,b可以取0.5mm,0.7mm,1.0mm,1.4mm。比如采用b=0.7mm,则依次为0.7mm,0.5mm,0.35mm,0.18mm,若需要的线宽类型较多,推荐采用b=1.0mm,系列值可为:1.0mm,0.7mm,0.5mm,0.25mm,0.13mm。
规范的线宽系列关系是:b,0.7b,0.5b,0.25b。b即最粗线,b可以取0.5mm,0.7mm,1.0mm,1.4mm。比如采用b=0.7mm,则依次为0.7mm,0.5mm,0.35mm,0.18mm,若需要的线宽类型较多,推荐采用b=1.0mm,系列值可为:1.0mm,0.7mm,0.5mm,0.25mm,0.13mm。
粗线与细线的宽度比例2:1。此外,将0.5mm和0.7mm两种线宽列为优先采用的粗线宽。