- 11
- Oct
1 èdtan dife rated pòt
The fire resistance time of Class B steel fire door shall not be less than 1.0 hour, and the hardware fittings used on the fire door must also be fire-resistant hardware fittings.
The fire resistance time of Class B steel fire door shall not be less than 1.0 hour, and the hardware fittings used on the fire door must also be fire-resistant hardware fittings.