c beam channel: 1.Material: zincalume,zinc 2.Thickness:1.0mm-3.0mm 3.height:100-350mm Adjustable and exchangeable C/Z purlins,Automatic purlin fabrication line which has reached advanced international level,High tensile(usual,over Q345)galvanized materials,Hole site and aperture can be prepunched according to requirements,For Z type purlins,We recommend continuous overlapping.