1)light structure 2)Hight hardness 3)easy for construction galvanized steel z purlin1.thickness:1.6-3.0mm2.width:45-85mm3.length:100-300mm4.color: Red ,white,grey,etc.5.standard:GB50018-20026.surface treatment:pre-galvanized, hot dipped galvanized, spray painting.7.length: as client's requirement8.usage: construction building, like warehouse volum and beam. Steel Z- purlin