FAQ

Yuanguangbao adopts S350GD-ZM275 hot-dip zinc-aluminum-magnesium high-strength steel.

• S: Structural steel
• 350: Yield strength of 350MPa
• GD: Hot-dip coating process
• ZM: Zinc-aluminum-magnesium alloy coating
• 275: Double-sided coating weight of 275g/m²

S350GD-ZM275 is a steel grade under European standard EN 10346:

• S = Structural, structural steel
• 350 = Minimum yield strength of 350MPa
• GD = Galvanized, hot-dip coating process
• ZM = Zinc-Magnesium, zinc-aluminum-magnesium alloy coating
• 275 = Coating weight of 275g/m² (total for both sides)

It features 350MPa strength plus 275g zinc-aluminum-magnesium coating, delivering high hardness and corrosion resistance, and the cut edges will not rust.

Yuanguangbao’s zinc-aluminum-magnesium coating adopts a high-magnesium & medium-aluminum formula: 3% Magnesium, 6% Aluminum and 91% Zinc. With 3% magnesium content, it reaches the top level domestically. The high-magnesium formula delivers superior self-healing performance on cut edges and outstanding corrosion resistance.

Cut-edge self-healing is a core advantage of zinc-aluminum-magnesium coatings. When steel is cut or punched, the exposed substrate at the cut edge is open to air. Magnesium elements in the coating dissolve in the water film on the cut surface and form a dense protective layer. It turns red rust into gray-black, locks corrosion and stops red rust from spreading. Yuanguangbao adopts a high-magnesium formula (3% Mg) for stronger cut-edge self-healing performance, guaranteeing 25-year anti-corrosion service life.

Yuanguangbao zinc-aluminum-magnesium coating has a total coating weight of 275g/m² for both sides, with a single-side thickness of approximately 19μm. It falls into the heavy coating grade to ensure long-term corrosion resistance.

Yuanguangbao’s Zn-Al-Mg coating contains 2-4% magnesium, adopting a high-magnesium and medium-aluminum formula (Mg: 2-4%, Al: 6-7%). Ordinary zinc-aluminum-magnesium coatings usually have 1-2% magnesium. Our 3% magnesium content represents the top ratio in China, delivering superior cut-edge self-healing performance and corrosion resistance.

Yuanguangbao Zn-Al-Mg: 4th-generation ZAM. It delivers over 10 times higher corrosion resistance, with cut-edge self-healing (magnesium migrates to form a protective film). It has 3% magnesium content (the highest in China) and requires low maintenance for 25 years.

Traditional galvanized steel: 1st-generation pure zinc coating. Its corrosion resistance is set as the baseline (1x). No cut-edge self-healing function, 0% magnesium content, and regular maintenance is required.

Yuanguangbao steel grade is S350GD with a minimum yield strength of 350MPa. It is over 1.5 times the yield strength of welded steel tubes, delivering far superior load-bearing and wind resistance compared to ordinary Q235/Q355 steel.