A.槽鋼 B.等邊角鋼 C.H型鋼 D.工字鋼
A.直徑48.3mm,厚度為3.6mm B.直徑58.3mm,厚度為3.6mm C.直徑48.3mm,厚度為4.6mm D.直徑58.3mm,厚度為4.6mm
A.100mm B.150mm C.200mm D.300mm