joistn.托梁
joist ceiling搁栅平顶
joisted floor搁栅搂盖
joist bearing托梁承座
joist bridging搁栅撑
joist and plank梁、板两用木料
joisted ceiling搁栅吊顶
joist rolling mil工字钢轧机
joist rolling mill工字钢轧机
joist shearing machine工字铁剪机
joist-frame structure桁架结构