Micro steel fiber

When sourcing for UHPC, the aspect ratio (length/diameter) is critical; typically, a ratio between 65 and 100 is preferred for optimal reinforcement. You must verify the tensile strength, which should ideally exceed 2,000 MPa to 3,000 MPa to ensure high energy absorption. Additionally, check the fiber diameter (usually 0.12mm to 0.25mm) and length (commonly 6mm to 15mm) to ensure uniform dispersion within the concrete matrix without clumping.

Suppliers should provide certification for ASTM A820/A820M (Standard Specification for Steel Fibers for Fiber-Reinforced Concrete) or the European equivalent EN 14889-1. For projects requiring high corrosion resistance, ensure the fibers have a copper coating or are made of stainless steel, and verify the ISO 9001 quality management certification of the manufacturer to ensure batch-to-batch consistency.

The most common treatment is copper coating, which serves two purposes: it prevents oxidation during storage and enhances the interfacial bond between the fiber and the cementitious matrix. For specialized chemical environments, you may require galvanized or stainless steel fibers to prevent long-term structural degradation due to rust.

Micro Steel Fibers are primarily used in UHPC, precast bridge segments, tunnel linings, and explosion-proof structures. The dosage varies significantly: for standard reinforcement, 20-40kg/m³ may suffice, but for Ultra-High Performance Concrete, the volume fraction can reach 1% to 3% (approx. 78-235kg/m³). Always request a technical data sheet (TDS) to align the fiber type with your specific structural load requirements.

The biggest risk is moisture damage and oxidation during sea freight. Ensure the supplier uses vacuum-sealed plastic inner packaging inside heavy-duty moisture-proof bags or wooden crates. Another risk is weight discrepancy; always stipulate that the final payment is subject to the weight recorded on the Bill of Lading (B/L) and consider a third-party pre-shipment inspection (like SGS) to verify both weight and tensile strength.

Steel fiber pricing is highly sensitive to raw material (wire rod) market fluctuations. It is advisable to negotiate a formula-based pricing linked to steel market indices for long-term contracts. For MOQs, while many suppliers set a 1-ton minimum, you can negotiate trial samples of 20-50kg to test mixability. Mentioning your annual projected volume can often secure a 5-10% discount compared to one-off spot purchases.

Steel fibers are high-density cargo, so 20ft containers are more cost-effective than 40ft containers to avoid exceeding weight limits. Ensure the supplier provides the correct HS Code (typically 7326.20) to avoid customs delays. Be aware of anti-dumping duties that some regions (like the EU or USA) may impose on specific Chinese steel products; always verify the Certificate of Origin to determine the applicable tariff rate.

Utilize the Secured Trading Service on Made-in-China.com to ensure payments are only released after you confirm receipt of goods. Always conduct a factory audit (virtual or physical) to confirm the supplier is a genuine manufacturer rather than a trading company, which ensures better technical support and lower pricing.