Stainless steel fasteners must provide reliable clamping, corrosion resistance, and consistent dimensions to support demanding industrial applications. If you select the wrong material or head design, you may encounter premature corrosion, damaged surfaces, or assembly difficulties. These issues can increase maintenance costs and interrupt production, particularly in marine equipment, automotive components, and precision machinery.
Shenhu Precision Parts (Hong Kong) Limited manufactures fasteners for industrial applications, drawing on experience dating back to 1984. Its product range includes the ISO 7380 stainless steel hex socket button head screw, available in SUS304/A2-70 and SUS316/A4-70 options. By comparing material grades, mechanical properties, and installation requirements, you can select stainless steel fasteners that suit your operating environment and assembly specifications.
What Are ISO 7380 Stainless Steel Button Head Screws?
An ISO 7380 screw features a rounded button head and an internal hexagonal socket. This design provides a compact fastening solution when you need a smooth head profile and a hex-key drive.
Unlike countersunk screws, which require a matching countersink for a flush finish, button head screws generally sit above the mounting surface. Their rounded profile can help reduce sharp-edge contact, making them suitable for equipment housings, electronic assemblies, and visible fastening points.
Key product features include:
- Standard: ISO 7380
- Material options: SUS304/A2-70 and SUS316/A4-70 stainless steel
- Diameter range: M1.6–M64, as specified for this product series
- Length range: 4–200 mm
- Thread options: Full-thread and partial-thread configurations
- Compliance: RoHS and EU REACH, according to the supplied product information
Confirm the required dimensions, thread configuration, and applicable ISO 7380 version with your supplier before ordering, especially for specialized or non-standard sizes.
Choosing SUS304 or SUS316 Stainless Steel Fasteners
Material selection directly affects how your fasteners perform in different environments. Both grades offer corrosion resistance, but SUS316 is particularly relevant when chloride exposure is a concern.
SUS304/A2-70 for General Industrial Use
SUS304 is suitable for many indoor industrial applications, electronic equipment, and outdoor installations where exposure conditions are moderate. The supplied specifications state a neutral salt spray resistance of at least 48 hours.
Consider SUS304 button head screws for:
- Industrial control cabinets and equipment housings
- General machinery assemblies
- Electronic devices and automotive interior components
- Applications requiring stainless steel fastening at controlled costs
SUS316/A4-70 for Marine and Corrosive Environments
SUS316 contains molybdenum, which improves resistance to chloride-related corrosion. According to the supplied specifications, the material contains at least 2% molybdenum and achieves at least 100 hours in neutral salt spray testing.
This grade may suit shipbuilding equipment, coastal installations, and components exposed to humid or chloride-rich conditions. However, actual service life depends on exposure, surface condition, maintenance, and installation practices.
SUS304 vs. SUS316: Key Specifications
| Specification | SUS304/A2-70 | SUS316/A4-70 |
|---|---|---|
| Typical application | General industrial environments | Marine and chloride-exposed environments |
| Neutral salt spray result | ≥48 hours | ≥100 hours |
| Tensile strength | ≥700 MPa, as specified | ≥700 MPa, as specified |
| Yield strength | ≥450 MPa, as specified | ≥450 MPa, as specified |
| Molybdenum | Not specified as an addition | ≥2%, as specified |
| Surface treatment | Natural passivation | Optional black passivation |
| Compliance | RoHS and EU REACH, as stated | RoHS and EU REACH, as stated |
These figures reflect the provided product information. Salt spray results are comparative test indicators, not direct predictions of service life. Confirm mechanical properties and test conditions against the material certificates and applicable standards before placing a critical order.
Manufacturing Precision and Quality Control
Shenhu Precision Parts (Hong Kong) Limited reports more than 40 years of fastener manufacturing experience, over 100 machines, and annual production capacity of 500 million pieces. The company also identifies IATF 16949, ISO 9001, and ISO 45001 among its system certifications.
For buyers sourcing precision stainless steel fasteners, these details provide useful starting points for supplier evaluation. Request current certification documents and confirm their scope when your purchasing requirements specify particular quality-management standards.
The supplied product information also identifies cold heading, precision thread rolling, and passivation as manufacturing processes. Reported head dimensional tolerance is ±0.02 mm. Confirm which dimensions this tolerance covers and whether inspection reports are available for your order.
How to Select the Right Stainless Steel Button Head Screws
Follow these steps before finalizing your purchase:
- Define the operating environment. Identify exposure to moisture, salt, chemicals, temperature changes, and vibration.
- Choose the material grade. Compare SUS304 and SUS316 against the actual corrosion risks and project requirements.
- Confirm dimensions. Specify nominal diameter, screw length, thread pitch, socket dimensions, and full-thread or partial-thread requirements.
- Check mechanical requirements. Verify strength, clamping load, and compatibility with the mating components.
- Review documentation. Request material certificates, relevant inspection records, and applicable RoHS and REACH documentation.
- Confirm order details. Agree on quantities, packaging, surface treatment, tolerances, and delivery requirements with Shenhu.
This process helps reduce specification mismatches and supports more consistent assembly across production batches.
Applications of ISO 7380 Stainless Steel Screws
The combination of a rounded head and hex socket makes these screws relevant to several industrial sectors:
- Electronics: Enclosures, industrial controllers, and equipment housings.
- Automotive: Interior components, instrument panels, and sensor assemblies.
- Medical equipment: Selected diagnostic equipment and instrument assemblies, subject to the application’s material and regulatory requirements.
- Marine equipment: Fastening applications where SUS316 may offer improved chloride corrosion resistance.
- Renewable energy and machinery: Equipment housings, support assemblies, and precision mechanical components.
Always evaluate the complete fastening system, including mating materials, required preload, vibration, and maintenance conditions.
FAQ
1. What is the difference between ISO 7380 and a countersunk screw?
ISO 7380 button head screws have a rounded head that generally remains above the surface. Countersunk screws use an angled head designed to sit flush when installed in a compatible countersink.
2. Should you choose SUS304 or SUS316 button head screws?
Choose SUS304 for many general industrial environments. Consider SUS316 where chloride exposure or marine conditions create greater corrosion concerns. The final choice should reflect actual operating conditions and project specifications.
3. Can you order custom sizes or packaging?
The supplied product information lists diameters from M1.6 to M64, lengths from 4 to 200 mm, and packaging options including single pieces, boxes of 100 or 500 pieces, and custom arrangements. Confirm availability, minimum order quantities, and any non-standard requirements directly with the supplier.
Conclusion
Selecting the right stainless steel fasteners requires more than matching a screw to a thread. You need to evaluate material grade, corrosion exposure, mechanical requirements, dimensional accuracy, and supporting quality documentation. Shenhu Precision Parts (Hong Kong) Limited offers ISO 7380 stainless steel hex socket button head screws in SUS304/A2-70 and SUS316/A4-70 options, supported by a manufacturing history dating back to 1984. Review your drawings, operating conditions, and certification requirements to determine the appropriate specification for your application.
Request a Quote from Shenhu: Share your required diameter, length, material grade, thread configuration, order quantity, and application environment with p2@szshenhu.com or call +86 13798584460. Ask for a product specification sheet and relevant quality documents before confirming your order.
