steel purlin 1,efficient lightweight; 2,ecomonical; 3,hole nicety; 4, ... and Z sections are accurately roll- formed from high strength galvanized steel to provide an efficient, lightweight, and economical roofing and walling ... 3.0adjustableC2202207060202.0~3.0adjustableC2502507070202.0~3.0adjustable Z Section Purlin DimensionsTypeDimensions(mm)Hole Pitch(mm)NoteHBbCthCustomized by customers’ own ...