Grade 4 Flange Nuts

Strength Grade: Grade 4
Tensile strength:≥400 MPa
Guaranteed load: ≥300 MPa
Flange face type: Smooth / Toothed
Operating temperature range: -20 °C to 80 °C

Advantages of Grade 4 Flanged Nuts

As an upgraded version of standard fasteners, Grade 4 flanged nuts offer significant practical advantages over traditional hex nuts.

One-piece design saves time, effort and costs

Featuring an integrated flange surface, there is no need to purchase or fit flat washers separately, which simplifies the assembly process and significantly improves installation efficiency. This makes them particularly suitable for high-volume assembly line operations, effectively reducing labour and component procurement costs.

Extra-large bearing surface to protect workpieces from damage

The widened flange increases the contact area and distributes clamping pressure, preventing damage to easily deformable workpieces such as thin sheets, plastics and aluminium during tightening. This effectively protects the base material, preventing localised dents and breakage.

Anti-slip and vibration-resistant, with high fastening stability

The serrated flange nut provides high friction and offers excellent resistance to vibration and loosening. It is suitable for equipment operating continuously under conditions of slight vibration, eliminating the problem of conventional nuts loosening and falling off during long-term use.

Wide versatility and high interchangeability

Compliant with national standard dimensions, they can directly replace standard hexagon nuts of the same specification without the need to alter the assembly structure. They are suitable for the vast majority of conventional fastening applications and are compatible with all types of national standard fasteners.

Classification of Flange Nuts

Performance Grade	Tensile Strength	Guaranteed Load	Applications	Material Requirements
Grade 4	≥400 MPa	≥300 MPa	Light loads, thin plates, non-critical structures	Low-carbon steel (Q235, etc.)
Grade 5	≥500 MPa	≥420 MPa	Medium loads, general structures	Medium-carbon steel (35#, etc.)
Grade 8	≥800 MPa	≥600 MPa	Drive systems, medium-heavy loads	Quenched and tempered medium-carbon steel
Grade 10	≥1000 MPa	≥800 MPa	Heavy-load critical components, safety components	Quenched and tempered alloy steel

Applications

Grade 4 flange nuts offer excellent value for money, are easy to install and provide outstanding anti-loosening performance; they are widely used in low-to-medium load fastening applications across various industries.

**General machinery manufacturing**
Assembly and fastening of small mechanical equipment, frames and housings, transmission components and tooling fixtures; suitable for mass production on assembly lines.

**Electromechanical and Electrical Equipment**
Fastening and installation of enclosures and cabinets, electrical control equipment, pumps and fans, plumbing and heating fittings, and electrical mounting brackets.

**Transport and Agricultural Machinery Components**
Assembly of electric vehicles, motorcycle parts, small transport facilities, agricultural machinery, and warehouse shelving.

**Construction and Hardware Engineering**
Light-gauge steel structures, equipment supports, guardrail frames, and fastening solutions for small-scale indoor and outdoor projects.

**Furniture and domestic equipment**
assembly scenarios requiring anti-loosening measures and protective plates, such as industrial furniture, equipment bases and lightweight fasteners.

Why Choose Us

As a direct manufacturer of Grade 4 flange nuts, we operate our own complete production, forging and galvanising lines, thereby eliminating mark-ups by intermediaries and offering factory-direct prices and original manufacturer quality to all our customers.

Full range of stock: We maintain a constant stock of the full range of GB Grade 4 flange nuts from M5 to M16. With ample stock, we can meet the needs of spot purchases, bulk engineering orders and long-term designated supply contracts, ensuring efficient and timely dispatch.
High value-for-money bulk supply: Through large-scale mass production and centralised raw material procurement to reduce costs, we offer more competitive pricing for equivalent quality. Large-volume orders are eligible for exclusive discounts, effectively reducing customers’ overall procurement costs.
Support for customisation: We can tailor non-standard specifications, special flange face thicknesses and custom plating processes to your requirements. We also support custom packaging and sorting, catering to brand-specific and project-specific supply needs.
Dual assurance of quality and after-sales service: All products comply with national standards and offer stable performance. We support sample testing and on-site factory inspections; for bulk orders, samples can be sent for confirmation beforehand. Unconditional returns and exchanges are available for quality issues, ensuring worry-free after-sales service.
One-stop supply of complementary components: We can supply matching bolts, spring washers and flat washers of the same specifications, enabling one-stop procurement of fasteners. This eliminates the hassle of liaising with multiple suppliers for customers and enhances procurement efficiency.