According to the different fire resistance of steel fire doors, their fire resistance can be divided into three grades: A, B, and c. Steel fire doors of different grades can be used in various places.

https://ztfiredoor.com/24683.html

single leaf fire door,automatic fire door hinges,steel fire related door,fire door 20 minutes,ce steel fire door,fire rated doors,steel fire stairway door,single leaf fire door,industrial fire safety door,60 minute fire door,steel fire related door,flush fire rates doors,single leaf fire door,fire emergency door price,bs steel fire door,fire rated doors,automatic fire rated door,steel fire related door,fire rated doors