There are ceiling by use of light steel keel keel and keel cut off, according to the form of V-shaped cross-section, C-, T-, L-keel. (1) Specifications Series keel off the main specifications into Q50, Q75 and Q100. Main specifications into the ceiling joists D38, D45, D50 and D60. (2) order the product labeling method mark for light steel keel: Product Name + Code + width + height sectional shape + + standard number plate thickness. Sectional shape such as "C" type, width 50mm, height 15mm, thickness of a plate. smm ceiling keel marked as: construction of light steel keel DC 5 0 XIS XI. SGBllg sl (3) the appearance of quality metal frame shape should be smooth, clear edges, burrs and deformation influential incision allowed to use. Not allowed to have galvanized layer from the skin, from tumors, loss and other defects. For corrosion, damage, dark spots, pitting and other defects, testing methods should comply with the requirements prescribed in Table 2-81. Appearance quality inspection, should be under bright lighting conditions at 0.5m away from the product, conduct a visual inspection. The surface should be galvanized metal frame rust, its double-sided galvanized: Excellence is not less than 120g / m * m, first grade of not less than 100g / m * m, not less qualified 80g / m * m Shandong Steel _ Ming Sheng _ Jining Zoucheng steel processing _ light steel keel