Light steel keel is mainly made of steel. It is thin-walled steel formed by cold bending process and serves as the core framing material for metal suspended ceilings and partition walls. The mainstream materials are divided into the following categories:
Basic mainstream material: Continuous hot-dip galvanized steel strip, galvanized steel sheet or cold-rolled steel sheet are the primary raw materials and the most common light steel keel materials on the market. The galvanized layer on the surface effectively isolates moisture and prevents rusting. For premium grade products, the double-sided zinc coating mass is no less than 120 g/㎡, delivering long service life under ordinary conditions.
Special upgraded material: Some keels for high-strength structures such as light steel villas adopt aluminum-zinc coated steel sheet, which consists of 55% aluminum, 43.4% zinc and 1.6% silicon. When the coating remains intact, its corrosion resistance is far better than ordinary galvanized steel sheet. Certain high-end types use G550 high-strength steel with yield strength ≥550 MPa for stronger load-bearing capacity.
Additional surface treatment: Some products are further coated with baking paint on the galvanized substrate to improve moisture and corrosion resistance, and achieve better decorative effect on exposed surfaces. These are mostly used for exposed grid ceiling systems.