Import A490m 10s Bolts Full Thread Dacromet — Buy in wholesale FOB from Supplier in China

The A490M 10S bolts are heavy hex structural bolts with full-thread engagement and a Dacromet coating, manufactured to the ASTM A490M specification for high-strength steel bolting in structural steel connections. The source lists available diameters from M12 to M36, covering the standard range for metric structural bolting in building frames, bridge girders, and tower assemblies. The Dacromet finish is a thin-film zinc-flake coating that provides cathodic corrosion protection without the hydrogen-embrittlement risk associated with electroplated zinc on high-strength steels above 12.9 grade equivalent.

Full-thread design means the threaded portion extends the full usable length of the bolt shank, allowing nuts to engage anywhere along the grip and improving load distribution in variable-thickness joints. ASTM A490M specifies a minimum tensile strength of 1,000 MPa and a minimum yield strength of 900 MPa for metric heavy hex bolts in this class, though buyers should request mill test certificates to confirm the actual values for the lot supplied. The Dacromet coating thickness typically ranges from 5 to 8 micrometres, providing salt-spray resistance of 500 to 1,000 hours depending on the specific formulation and topcoat presence. The black surface appearance mentioned in the source is consistent with standard Dacromet colour, though this is aesthetic rather than a separate coating layer.

These bolts serve structural steel fabricators, bridge contractors, power-transmission tower erectors, and heavy equipment manufacturers who need preloaded friction-grip connections. The full-thread configuration is particularly valued in field-bolting scenarios where grip length varies and maximum thread engagement is needed for tensioning consistency. No minimum order quantity, lead time, or pricing is stated in the source, so buyers must confirm these terms directly with Ningbo S&D Metalwork Co., Ltd. Certification claims such as ISO are mentioned only in generic text without scope or certificate number, and should be verified before relying on them for project compliance.

Ningbo S&D Metalwork Co., Ltd. is located in Yinzhou District, Ningbo 315114, Zhejiang Province, China. The fue supplier tier is imported and the trust tier is harbor, indicating a basic marketplace listing without verified on-site audit documentation. The response rate shows 0.00 percent with zero average response hours, so no communication reliability data is available from the source profile.

The company profile does not state year of establishment, factory floor area, number of employees, annual revenue, or specific clientele. No certification documents, test laboratory affiliations, or manufacturing scope details are provided beyond generic references to ISO standards. The Yinzhou District location places the company within Ningbo's established metalworking and fastener manufacturing cluster, but this geographic concentration does not independently confirm production capability or quality-system maturity. Buyers should request a factory profile, quality-manual summary, and recent third-party audit report before committing to structural-bolt supply for critical applications.