... purlinHole Sizeφ8,φ10,φ12,φ14,φ16,φ18φ8,φ10,φ12,φ14,φ16,φ1810*20,12*20,16*20,14*22,18*18 ... ,18*2210*20,12*20,16*20,14*22,18*18,18*22Surface Treatmenthot dipped galvanizedhot ... reached advanced international levelHigh tensile (usually over Q345)galvanized matrirals; hole site and aperture can be prepunched according to requirement; for ...