Class a fire windows. The number at the back refers to the size of the window.
FM, it should be the door and window number.
FM may be a security door or a fire door. Security doors are more likely. Usually, fire doors will be marked with protection grade, such as FM-0 1 (B).
Extended data:
1, the formal decoration design should be signed by the designer, the person in charge of the decoration drawings, the reviewer and the proofreader, and stamped with the seal and the registered practice seal.
2. In decoration design drawings, the length is generally in mm, unless otherwise specified; Pay attention to the combination of "decoration material description" and other drawings when looking at the pictures. In the "Description of Decoration Materials", each item is marked with "√", which is the practice adopted in the design. What is not ticked is not the design practice.
3. For example, in the decoration design, "c20 reinforced concrete jl(240400) is equipped with 4φ 16 winding φ 6 @ 200 stirrups." The foundation beam of reinforced concrete structure with strength C is 240mm wide and 400mm high. It is equipped with four main steel bars with a diameter of 16mm (16 mm), and a rectangular ring of steel bars with a diameter of 6 mm is hoop every 200 mm (the rectangular ring is about 340-350mm long and about 180 mm- 190 mm wide).
4. For example, in the decoration design: "c20 concrete column (240240) with 4φ 12 hoop] 6 @ 200." Where "] 6 @ 200" is a nonstandard label and should be "φ 6 @ 200". It is interpreted as: a c20-strength small beam of reinforced concrete structure, with a section length of 240mm and a width of 240mm, is equipped with four main bars with a diameter of 12mm (12mm), and a rectangular steel mesh with a diameter of 6cm is hoop every 200mm. The height of the column depends on the height of the floor marked by the project minus the height of the ring beam and the thickness of the panel, because the ring beam and the panel are poured together.
Baidu Encyclopedia-Architectural Drawing