Product Overview
The High-Strength Nut is a critical structural fastener engineered to match the performance of high-tensile bolts and studs in demanding applications. Manufactured from medium carbon or alloy steel, then quenched and tempered, it achieves superior mechanical properties—including high proof load, tensile strength, and hardness—to prevent stripping, thread deformation, and premature failure under extreme static and dynamic loads. These nuts are essential for safety-critical bolted joints in construction, heavy machinery, wind energy, and transportation infrastructure.
Key Features & Benefits
Exceptional Load-Bearing Capacity: Designed to develop the full strength of matching high-strength bolts (e.g., Grade 8.8, 10.9, 12.9), ensuring the joint fails in the bolt rather than the nut.
Reliable Performance in Severe Conditions: Maintains clamp force under vibration, impact, and high stress, preventing joint loosening.
Enhanced Safety Margin: The quenched and tempered heat treatment provides a uniform microstructure, offering high resistance to brittle fracture and fatigue.
Dimensional Consistency: Precision-formed threads ensure accurate pitch and lead, facilitating smooth engagement and optimal load distribution across all threads.
Material & Process Integrity: Manufactured with full traceability from certified raw material to final heat treatment, guaranteeing consistent property class.
Material Specifications & Property Classes
| Property Class (ISO) | Equivalent Grade (ASTM) | Material & Process | Proof Load Stress (min) | Core Hardness (HRC) | Typical Applications |
|---|---|---|---|---|---|
| Class 8 | Grade 5 | Medium Carbon Steel, Quenched & Tempered | 580 MPa | 22-32 | General structural, industrial machinery, agricultural equipment. |
| Class 10 | Grade 8 | Medium Carbon Steel / Boron Steel, Quenched & Tempered | 830 MPa | 28-36 | High-stress structural connections, truck & trailer, lifting equipment. |
| Class 12 | – | Alloy Steel (e.g., 34Cr), Quenched & Tempered | 970 MPa | 33-39 | Most demanding applications: wind turbine flanges, heavy-duty mining equipment, high-pressure valves. |
Standard Series & Specifications
Our High-Strength Nuts are produced to meet or exceed the mechanical and dimensional requirements of major international standards:
Hex Nuts (Style 1 / 2): ISO 4032 / 4034 (Metric), ASME B18.2.2 Heavy Hex Nuts (Imperial), DIN 934 / 6915.
Flange Nuts: ISO 4161, DIN 6923. Integrated washer face distributes load and eliminates the need for a separate washer.
Heavy Hex Nuts: ASME B18.2.2, ISO 10433. Thicker dimensions for extra strength and bearing surface.
Coupling Nuts: For joining two threaded rods or studs end-to-end.
Size Range: Metric: M6 to M64. Imperial: 1/4″ to 2-1/2″ and larger.
Available Surface Finishes & Corrosion Protection
| Finish Type | Specification / Standard | Typical Salt Spray Resistance (Neutral) | Key Application & Note |
|---|---|---|---|
| Plain, Oiled (for subsequent coating) | – | – | Often supplied for projects requiring on-site hot-dip galvanizing. |
| Electro-Zinc Plated (Blue/Yellow/Trivalent) | ASTM B633 | 72 – 120 hours to white rust | General corrosion protection for indoor/controlled environments. |
| Hot-Dip Galvanized (HDG) | ASTM A153 / ISO 10684 | Long-term (variable) | Standard for outdoor structures. Thick, sacrificial coating for severe atmospheric corrosion. |
| Zinc Flake Coating (Geomet®, Delta Protekt®) | Proprietary / ISO 10683 | 500 – 1000+ hours | High-Performance. Superior corrosion resistance, excellent friction control, RoHS compliant. Used in automotive and offshore. |
| Mechanical Galvanizing | ASTM B695 | Good (thicker than electro-zinc) | Provides uniform coating without risk of hydrogen embrittlement. |
| Black Oxide/Phosphate & Oil | MIL-DTL-13924 | Minimal | Mainly for appearance, break-in lubrication, and mild indoor protection. |
Quality Assurance & Traceability
Manufacturing Standards: Production is governed by a certified ISO 9001:2015 Quality Management System, with additional compliance to IATF 16949 for automotive and EN 14399 for preloaded structural systems (HSFG).
Rigorous Testing: Each batch undergoes mandatory hardness testing, proof load testing (per ISO 898-2 or ASTM A563), and dimensional verification. For higher classes, wedge load testing is performed.
Full Documentation: We provide full material traceability with Mill Test Certificates (MTC) and Certificates of Compliance (CoC) that include chemical analysis, mechanical test results, and heat treatment batch records. Products are marked with the property class identifier for easy identification.
About Our Manufacturing
Our High-Strength Nuts are engineered and produced by Hebei Wohe Fastener Manufacturing Co., Ltd., a manufacturer with deep expertise in metallurgy and structural fastener production. Our integrated facility features in-house heat treatment lines with precise atmosphere control and temperature profiling to ensure the required strength and toughness are achieved consistently. Equipped with modern cold-forming and thread-rolling technology, coupled with a dedicated quality laboratory, we supply certified high-strength fastening solutions to the construction, energy, and heavy equipment sectors worldwide, meeting the most stringent project specifications.
Technical & Commercial Support:
Technical Data: Comprehensive specification sheets (PDF) and 3D CAD models (STEP) are available.
Samples & Testing: Pre-production samples can be provided for qualification and assembly testing.
Customization: We support production of non-standard dimensions, special chamfers, unique markings, and proprietary coatings.
Packaging: Standard export packaging in cartons, drums, or pallet boxes. Custom packaging and marking available.
MOQ: For standard grades and sizes, Minimum Order Quantity starts from 5,000 pieces. Project-based orders are negotiable.
Lead Time: Standard items: 20-25 working days. Custom or large-volume project orders: quoted based on requirements.
Important Note: High-strength nuts must be used in conjunction with bolts or studs of matching or higher property class. Proper installation, including the use of calibrated torque or tensioning equipment, is critical to achieving the designed preload and joint integrity. The information provided is for general reference; final specification and validation for the specific application are the responsibility of the end user or design engineer.
