Import Astm A307 Grade A Hex Bolts — Buy in wholesale FOB from Supplier in China

These ASTM A307 Grade A Hex Bolts from Ningbo Steel Bolt Co., Ltd are unified coarse thread carbon steel fasteners with hexagon heads, manufactured to ASTM A307 mechanical specifications with provision for fine thread variants upon request. The Grade A classification limits application to general purpose use with a tensile strength of 60,000 psi minimum, as against the broader Grade B range. Heat treatment is applied during manufacture, with surface options spanning hot-dip galvanised, black oxide, zinc electroplated, yellow zinc plated, plain, and Dacromet coating for varying corrosion resistance requirements.

Carbon steel remains the base material for Grade A, with stainless steel offered as an alternative material across the supplier's broader fastener range rather than for this specific ASTM grade. Fine thread (UNF) hexagon heads are noted as available, expanding the standard coarse thread offering for applications requiring finer adjustment or reduced thread stripping risk in thinner materials. Connection type is specified as common bolt, indicating through-hole clearance fit rather than structural bearing bolt or tension control configuration. Surface treatment selection should match environmental exposure, with HDG and Dacromet offering superior salt spray resistance over standard zinc or black finishes.

Engineering procurement teams, steel fabrication contractors, and maintenance supply distributors form the core buyer base for this fastener grade. Fine thread variants suit precision machinery, automotive aftermarket, and instrumentation applications where vibration resistance and fine adjustment outweigh the superior thread engagement of coarse series. Buyers should confirm whether heat treatment refers to stress relief or through-hardening, request actual hardness values, and verify that fine thread stock is carried or produced to order given the standard coarse thread dominance in ASTM A307 Grade A commerce.

Ningbo Steel Bolt Co., Ltd is located at Panjiashan, Xiepu Town, Zhenhai, Ningbo, Zhejiang, China 315200. The supplier profile indicates a harbor trust tier with no recorded response activity, as both response rate and average response hours show zero values. No factory size, year of establishment, annual revenue, employee count, or named client references appear in the disclosed information. The address places the operation within Ningbo's established metalworking and port logistics corridor.

This listing presents a commitment to rapid response and short delivery times alongside custom design and logo services, though these claims are not independently verified. The product range spans carbon steel, stainless steel, and alloy steel fasteners with multiple surface treatment capabilities including specialised coatings such as Dacromet. Buyers should treat promotional statements as unverified until supported by factory audit, sample evaluation, and reference checks from existing customers in their market.