... *90Standard:41*41,41*21Wall thickness:1.52.7mmLength:10,20(3m,5.8m,6m)C purlin is the main structure in ... span in the door frame, if we adopt asingle limb C steel used for beam-column elements, the construction of the ... , while it will be more convenient to components transportation, installation. C-beam flangewidth, nodes on the beam diameter bolts connecting nodes ...