EN 14399-3 HR Hot-Dip Galvanizing Class 10.9 Hexagon Head Bolt for Preloaded Joints
CE-marked HR bolting assemblies per EN 14399-3 (System HR) for preloaded joints in steel structures to Eurocode 3 (EN 1993-1-8). Each assembly comprises: property class 10.9 hexagon head bolt (large widths across flats), property class 10 hexagon nut, and through-hardened washer to EN 14399-6. Sizes M12–M36. Preload achieved by bolt elongation, providing controlled ductility and tolerance to moderate overtightening.
Bolts threaded before galvanizing to tolerance class 6az (ISO 965-5), accommodating zinc coating of 40–80 μm. After galvanizing, external thread mates with internal thread 6H. Nuts (class 10) have 6H or 6AZ internal threads; proof load stress 1160 MPa.
Bolt: class 10.9 per EN ISO 898-1 (tensile strength ≥1000 MPa, yield ≥900 MPa). Nut: class 10 per EN ISO 898-2, style 1 normal height (EN ISO 4032). Thread length per ISO 888 (longer than standard) ensures preload ≥0.7 × fub × As. Ductility via plastic elongation of shank; bolt fracture during tensioning is the intended failure mode, indicating overtightening.
Washers (only under nut) per EN 14399-6: Vickers hardness 300–370 HV, through-hardened to distribute preload and prevent embedment. Complete hot-dip galvanized assembly complies with EN ISO 10684 and EN 1090-2. All components traceable with batch-specific inspection certificate 3.1 per EN 10204.
A: We are factories, mainly producing fasteners, such as nuts, bolts, screws and rods, and meanwhile, we also manage other hardware products.
A: Our factory is located in Jiaxing City, Zhejiang Province with a good location and convenient transportation, which is next to Shanghai Port, Ningbo Port and Zhapu Port.
A: "Quality is priority" we supervise each production link and we always attach great importance to quality controlling from the beginning to the end.
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.