... world installtion faster please contact us C purlin specification:C100*40 C 100*50 C120*40C120*50 C140 ... .52.7mmLength:10,20(3m,5.8m,6m)C purlin is the main structure in the bulding ... the door frame, if we adopt asingle limb C steel used for beam-column elements, the construction ... will be more convenient to components transportation, installation. C-beam flangewidth, nodes on the beam diameter bolts ...