Steel fire doors are divided into the following three types: the fire resistance time of Class A steel fire doors shall not be less than 1.5 hours; the fire resistance time of Class B steel fire doors shall not be less than 1.0 hours; the fire resistance time of Class C steel fire doors shall not be less than 1.0 hours. less than 0.5 hours.

steel door security bar,fire rated door kick plate,best steel security door,buy steel security door,

fire resistant door manufacturer,steel security door,steel door security bar,fire proof door material,best steel security door,fire rated door thickness,buy steel security door,emergency exit door use,fire rated door 90 minute,labeled panel door,

wooden fireproof doors,steel door security bar,emergency exit door use,fire rated door ul,fire rated door residential