The core rust prevention ability of hot-dip galvanized steel coils is determined by the weight of the zinc layer. The industry commonly uses zinc layer specifications of 30g/㎡, 60g/㎡, 100g/㎡, 140g/㎡, 180g/㎡, and 275g/㎡. The thickness of the standard zinc layer varies greatly depending on the usage environment and industry. Longyi Import and Export combines more than 30 export project cases to organize the selection criteria for zinc layers in different scenarios, helping overseas buyers place accurate orders and avoid rapid rusting of the zinc layer due to thinness or increased procurement costs due to excessive zinc layer.

Inland dry areas (inland in Central Asia, inland in Africa, and inland cities in Europe and America): low air humidity, no salt spray, and less industrial pollution. Z30-Z80 (30-80g/㎡) zinc layer can be used for conventional building enclosures, temporary warehouses, and agricultural greenhouse skeletons. Outdoor use for 8-10 years without obvious rust, with the lowest procurement cost, suitable for large-scale low-cost infrastructure projects. For indoor use scenarios of household appliance casings, Z60-Z100 fingerprint free galvanized coil is recommended to balance rust prevention and appearance effects.

Mild humidity in suburban areas, ordinary urban environment (Southeast Asian inland cities, European inland towns): abundant rainfall, no seawater salt spray, recommended Z100-Z140 zinc layer for factory roofs, light steel keel, and highway inland guardrails. The thickness of the zinc layer is moderate, balancing cost and corrosion resistance, and the outdoor service life is 10-13 years. It is the most commonly used zinc layer specification for civil buildings worldwide. The mainstream zinc layer for Longyi spot galvanized coils is 100/120g/㎡, with the fastest delivery speed.

Coastal high salt spray areas (Vietnam coast, Thai ports, Middle East coast, European Mediterranean coast): Sea breeze carries salt and has strong corrosiveness. Ordinary thin zinc layers will rust points within 1-3 years, and Z140-Z180 thick zinc layers must be selected. Some permanent factories and coastal storage projects in ports can customize zinc layers of 200g/㎡ or more to resist salt spray erosion. Outdoor stable use for more than 12 years greatly reduces maintenance and renovation costs in the later stage.

Heavy industry pollution areas (chemical plant areas, smelting plants, coal mine warehouses): The air contains acidic dust and corrosive exhaust gas, with a corrosion rate far exceeding that of ordinary environments. The minimum Z180 zinc layer for engineering procurement is recommended, and Z275 high zinc layer galvanized coils are recommended for heavy steel structures and equipment bases. Sacrificial anode protection capability is fully utilized, suitable for severe corrosion industrial scenarios.
Special scenarios in transportation and agriculture: Highway and highway guardrails are exposed to rainwater and snow melting agents all year round, and the Z120-Z180 zinc layer is uniformly required; The buried components of agricultural grain silos and wet farming sheds are directly coated with Z180 thick zinc layer to resist dual corrosion from soil and water vapor.

All galvanized steel coils of Longyi have a uniform and stable zinc layer, with errors controlled within the allowable range of national and European standards. Each coil comes with a zinc layer detection data report, which supports third-party weighing and testing. When placing an order, customers only need to inform us of the project's environment and industry of use, and our sales engineers will automatically match the optimal zinc layer specifications without the need for customers to calculate on their own; Simultaneously supporting the mixed shipment of multiple zinc layers for the same order, meeting the synchronous procurement needs of multiple category projects. When matching with corresponding color coated products, we will also match the zinc layer substrate to ensure long-term anti-corrosion of the whole. Please feel free to consult for the purchase quotation of zinc layer for each scene.