Tungsten bar

When evaluating Tungsten Bars, the most critical factor is purity, which should typically be 99.95% or higher for industrial applications. You must also specify the density, as high-quality sintered tungsten should reach approximately 19.3 g/cm³. Additionally, clarify the surface finish requirements—whether you need black (as-forged), cleaned, or ground/polished surfaces—as this impacts both the price and the suitability for further machining.

You should request data on tensile strength and hardness (typically measured in Rockwell or Vickers). For high-temperature applications, verify the recrystallization temperature to ensure the bar maintains its structural integrity. If the bars are intended for electrodes or vacuum furnace parts, ensure they have low vapor pressure and high thermal conductivity.

Reliable suppliers should provide Material Test Reports (MTRs) or Mill Test Certificates (MTC) that comply with ASTM B760 (for plates/sheets) or ASTM B777 (for high-density tungsten alloys). For international trade, ensure the supplier adheres to ISO 9001 for quality management and provides a Conflict Mineral Reporting Template (CMRT) to prove the tungsten is ethically sourced and Conflict-Free.

Tungsten bars are primarily used as raw materials for drawing tungsten wire, manufacturing heating elements for vacuum furnaces, and producing TIG welding electrodes. They are also essential in the aerospace and defense sectors for balance weights, and in the medical industry for radiation shielding due to their high density.

Tungsten is a high-value metal, making it a target for fraud. Always request a pre-shipment inspection (PSI) by a third party like SGS or Intertek to verify density and chemical composition via X-ray fluorescence (XRF) or ICP-OES. Avoid suppliers offering prices significantly below the current market rate on the London Metal Exchange (LME) or specialized tungsten price indexes.

Due to the extreme density and weight of tungsten, packaging must be robust. Ensure the supplier uses reinforced wooden crates with internal padding to prevent shifting during transit, which can damage the container or the product. For cross-border shipping, confirm the HS Code (typically 8101.96) to accurately calculate import duties and ensure compliance with dual-use export controls if applicable.

When sourcing via Made-in-China.com, look for 'Diamond Members' or 'Audited Suppliers' to ensure business legitimacy. Negotiate based on volume-tiered pricing; for tungsten, even a 5% discount on bulk orders can result in significant savings. Request payment terms like LC (Letter of Credit) or use secured trade services to protect your funds until the goods pass quality inspection.

Tungsten is often classified as a critical raw material. Be aware of anti-dumping duties that may exist between specific countries (e.g., China to the EU or USA). Always check for export license requirements from the supplier's side, as some high-purity tungsten grades are subject to strategic resource monitoring.