... (according with GB/T700-1988) 4.ladder stand and steel bridge use steel tube ( diameter 48mm,thicker≥2.5mm accord with GB ... non-faded ,and surface coating use ployester resin finish .anti-skidding safety. 6.welded steel use argon arc welding and co2 ... non pollution , un-stimulating ,anti-static , 3.stainless steel ,other parts use kirsite pressure casting 4. process temperature:200degree,not change ...