20工字钢标准? 时间:2026-01-31 04:09:00 浏览:868次 20a号工字钢规格:h=200mm,b=100mm,d=7mm,t=11.4mm,t=9mm,r1=4.5mm20b号工字钢规格:h=200mm,b=102mm,d=9mm,t=11.4mm,t=9mm,r1=4.5mm 标签:工字钢,标准