The fire resistance of steel fire doors is different. The fire resistance can be divided into three grades: A, B and C. Steel fire doors of different grades can be used in various places. The advantages of steel fire doors make them occupy a large market share in public buildings. It is widely used in hospitals, schools and shopping malls.

ZHTdoors pòt dife, 31 ane eksperyans nan pwodiksyon nan pòt dife ak fenèt yo. Pwensipal UL dife pòt yo, EN dife pòt yo, BS EN dife pòt yo, elatriye,.Nou gen certification.ZHTdoors sipòte OEM ak konsepsyon gratis.Avantaj nou yo: bon kalite, pri faktori, bon sèvis.Byenveni pou konsilte nou.