Products Detail

We supply three series of high-strength HV hex nuts for structural bolting assemblies: EN14399-4 10 HV Hex Nuts, DASt021 10 HV Hex Nuts and DIN 6915 High-Strength HV Hex Nuts.
EN14399-4 10 HV Hex Nuts are our flagship core products specially designed for high-strength preloaded structural bolting assemblies. Complying with stringent EU industry regulations, these high-performance nuts fully meet ISO 898-2 requirements with stable mechanical properties, accurate preload performance and excellent structural coordination. All export products hold valid CE certification to meet EU market access and construction standards. They are widely used in wind towers, nacelle fabrication, building engineering and heavy load-bearing structures as essential fasteners for high-spec pre-tightening structural systems.
DASt021 10 HV Hex Nuts are developed for high-standard wind power fastening applications. DASt-Richtlinie 021, issued by the German Wind Energy Commission and extended from DIN 6915, covers oversized fasteners out of the scope of common general standards, with tighter machining tolerances and higher technical thresholds. Available in Class 8 and Class 10, these nuts are forged from premium carbon and alloy steel, supporting sizes M39–M72. They feature excellent mechanical strength, stable hardness and superior fatigue resistance, ideal for harsh wind farm environments and widely adopted in wind turbine structural joints, tower fastening and wind equipment assembly for onshore and offshore wind projects.
DIN 6915 High-Strength HV Hex Nuts are standard heavy hex nuts for high-preload steel structure bolting assemblies. With enlarged across-flats dimensions and optimised geometry, they offer larger bearing area, better clamping stability and higher rigidity than ordinary hex nuts. Supplied in Class 8 and Class 10 grades and forged from high-quality carbon and alloy steel, the size range covers M12–M64. Products comply with DIN EN 20898-2 and match perfectly with DIN 6914 high-strength hex bolts to form complete bolting sets. After quenching and tempering heat treatment, they deliver stable tensile strength and outstanding fatigue resistance, resisting loosening and fatigue failure under alternating loads, vibration and wind impact. Typical applications include steel structures, building engineering, power generation, wind power facilities and heavy industrial equipment.

Manufacturer Advantages:
As a professional manufacturer focusing on high-strength HV structural nuts, we have mature independent R&D, precision forging and full-scale production capabilities covering EN14399-4, DASt021 and DIN 6915 series. We master both cold forging and hot forging technologies and support standard batch production as well as customised sizes to satisfy diverse engineering demands.
Equipped with an in-house laboratory, we implement full-process quality supervision from raw material selection, precision forging and heat treatment to finished product inspection. Every batch undergoes strict performance tests including mechanical property detection and torque verification, to guarantee stable, traceable and consistent batch quality.
Ningbo Haixin Hardware has held official CE EN14399 certification since 2007, with nearly 20 years of certified fastener export experience. We completed the full factory audit and sample testing for DASt021 certification, and are well acquainted with EU and German wind power mandatory standards for HV fasteners. With reliable quality and cost-effective pricing, our products have been exported to more than 10 countries worldwide and recognised by global engineering customers. We aim to build long-term, stable and win-win cooperative partnerships as your trusted Chinese supplier. Factory visits and technical negotiations are warmly welcomed.

  

Surface Finishing: Black Oxide, Zinc Plating, Hot-Dip Galvanizing, Dacromet, Delta, Geomet, Magni, Teflon, Blue Wax, Molybdenum Disulfide (MoS₂) Coating