Import A325m 8s Heavy Hex Structural Bolts — Buy in wholesale FOB from Supplier in China

The A325M 8S heavy hex structural bolt is a metric high-strength fastener manufactured to ASTM A325M Grade 8S standards, with a minimum tensile strength of 800 MPa and yield strength of 640 MPa. Ningbo S&D Metalwork Co., Ltd. supplies these bolts in sizes ranging from M12 to M36, with thread pitches conforming to ISO metric coarse standards. The heavy hex head design provides 18% greater bearing surface than standard hex bolts, distributing clamping load more effectively in structural steel connections.

These bolts are produced from medium-carbon alloy steel, typically 4140 or equivalent, quenched and tempered to achieve the required mechanical properties. Surface treatments include plain black oxide, zinc electroplating (typically 5-12 micrometres), or hot-dip galvanising (typically 50-85 micrometres coating thickness per ISO 1461). The 8S designation indicates a structural bolt with controlled thread length and full body diameter, suitable for use with structural nuts conforming to ASTM A563M Class 8S or ASTM A194M Grade 2H. Buyers should verify Charpy V-notch impact testing requirements for applications below -20 degrees Celsius, as standard A325M bolts are not rated for low-temperature service without supplemental specifications.

Primary applications include steel-frame buildings, bridges, transmission towers, and heavy machinery assembly where slip-critical or bearing-type connections are specified. The bolts are installed with calibrated tensioning methods (turn-of-nut or direct tension indicators) to achieve the prescribed preload. Buyers should confirm with Ningbo S&D Metalwork Co., Ltd. whether the supplied bolts include matching nuts and hardened washers, as complete assemblies are often required for structural certification. The supplier's location in Ningbo, Zhejiang Province, offers access to Shanghai and Ningbo-Zhoushan ports for containerised export.

Ningbo S&D Metalwork Co., Ltd. is based in Yinzhou District, Ningbo, Zhejiang Province, China (postal code 315114). The company operates as an imported-tier supplier on its marketplace platform, with a harbour trust designation. Response rate data shows 0.00% with zero average response hours recorded, indicating no verified communication history is available through the platform. Buyers should conduct independent due diligence, including direct contact and third-party verification, before placing orders.

The supplier's profile does not disclose factory ownership, production capacity, workforce size, annual revenue, or specific clientele. No ISO 9001, ISO 14001, or IATF 16949 certification status is listed. The source description references flexible MOQ and trade terms including L/C and T/T, though exact minimum quantities and pricing are not specified in the available data. Buyers should request a current factory audit report, quality management system certificate, and sample batch with mill test certificates to assess suitability for structural fastener procurement.