I purchased galvanized steel sheets from their company earlier this year. They provide raw material certificates with clearly stated chemical composition and mechanical properties (yield strength, tensile strength, etc.), fully compliant with national standards. The adhesion between their material substrate and zinc coating is excellent; as long as your mold and process parameters are appropriate, there have been almost no instances of large-area zinc coating peeling or noticeable micro-cracks during bending.

If you're still concerned, I strongly suggest they send a sample for testing first. That's what we did; we bent it a few times, tested the zinc coating, and once the results came back, we had a clear understanding of its quality.

Corrugated culverts buried in ordinary soil foundations often experience a certain degree of subsidence after a period of time, and the subsidence is usually greater in the middle of the pipe than at both ends.
Therefore, the corrugated culvert pipes laid under the embankment should have an upward pre-camber in the middle. The pre-camber is determined by a comprehensive consideration of factors such as the potential settlement of the foundation, the longitudinal slope of the culvert bottom, and the height of the fill. It is usually 0.3% to 1% of the pipe length, and the maximum is no more than 2%, to ensure that no depression or landslide occurs in the middle of the pipe.

We have contacted you via email and website message regarding your required HRB400 steel bars (8/12/16mm x 12 meters). Based on your purchase quantity of 200 to 500 metric tons and FOB delivery terms at major Chinese ports, our professional purchasing team will directly calculate costs for you and provide the most competitive comprehensive solution.

Please confirm the following information: Precise purchase quantity: Please provide your planned minimum order quantity (e.g., 300 tons or 500 tons) so we can give you the most accurate quote.
Target port of shipment: Please inform us of your preferred major Chinese ports (e.g., Tianjin Port, Shanghai Port, Qingdao Port, etc.) so we can calculate the accurate FOB costs.
Sample requirements: We can immediately coordinate and send standard samples from our partner steel mills' inventory according to your requirements. Please provide your detailed mailing address and contact information.
Upon receiving the above information, our team will send you a formal quotation via email as soon as possible, and detailed delivery date.

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