Sintered bush

Buyers should prioritize ASTM B438 (Bronze) or ASTM B439 (Iron) standards. The most common material is CuSn6Zn6Pb3 (Bronze) for high-speed, low-load applications, or Iron-Graphite for heavy-duty, low-speed scenarios. Ensure the porosity levels are between 18% and 25% to guarantee sufficient oil retention for self-lubrication.

Sintered bushes require high precision, typically following ISO 2795 standards. You must specify H7/g6 or G7/s6 tolerances depending on the fit. Request the supplier to provide Coordinate Measuring Machine (CMM) reports and verify the concentricity and perpendicularity to prevent premature wear in the final assembly.

The critical metric is the PV Value (Pressure x Velocity). Ensure the product meets your specific application requirements (e.g., PV limit of 1.8 - 2.5 MPa.m/s for bronze). Additionally, confirm the impregnation oil type (e.g., synthetic vs. mineral) to ensure compatibility with the operating temperature range, typically -10°C to +100°C.

Suppliers must hold ISO 9001:2015 for general quality management. For automotive applications, IATF 16949 is essential. Furthermore, ensure compliance with RoHS and REACH directives to guarantee the absence of hazardous substances like lead or cadmium, which is vital for export to the EU and US markets.

Sintered parts are prone to oxidation if not handled correctly. Insist on VCI (Volatile Corrosion Inhibitor) packaging and vacuum sealing. Before final payment, hire a third-party inspector to perform a crushing strength test (K-factor) and oil content verification to ensure the batch meets the technical datasheet.

Focus on Total Cost of Ownership (TCO) rather than just the unit price. Request a breakdown of tooling costs (mold fees) versus unit price. For long-term partnerships, negotiate a price sliding scale where the unit price decreases as your annual cumulative volume reaches specific milestones (e.g., 10k, 50k, 100k units).

Sintered bushes are heavy but fragile if dropped. Specify reinforced wooden crate packaging for sea freight to prevent pallet collapse. For shipping to the US or Europe, ensure the supplier provides a Certificate of Origin to potentially leverage trade agreements and reduce import tariffs.

Always use Secured Trading Services provided by platforms like Made-in-China.com to protect your down payment. Avoid direct wire transfers to private accounts. Conduct a factory audit (virtual or physical) to confirm the supplier has in-house sintering furnaces and sizing equipment rather than being a pure trading company.