A4 fasteners are made from marine-grade stainless steel (typically AISI 316). They’re chosen when strength must be combined with excellent corrosion resistance.

Key Benefits

1. Superior corrosion resistance

   • Excellent performance in saltwater, coastal, and marine environments

   • Highly resistant to chlorides, acids, and industrial chemicals

2. Ideal for harsh conditions

   • Suitable for outdoor, chemical, and high-humidity applications

   • Performs well where A2 (304) fasteners may corrode

3. Good mechanical strength

   • Common strength class: A4-70 (≈700 MPa tensile strength)

   • Reliable for structural and load-bearing assemblies

4. High temperature resistance

   • Maintains properties at elevated temperatures better than carbon steel

5. Low maintenance & long service life

   • No need for protective coatings or frequent replacement

   • Reduces lifecycle cost despite higher initial price

6. Non-magnetic (generally)

   • Useful in electrical, electronic, and sensitive equipment installations

7. Clean & aesthetic finish

   • Preferred in food processing, pharmaceutical, and architectural uses

Typical Applications

• Marine & offshore equipment

• Chemical plants and refineries

• Coastal buildings and infrastructure

• Food & dairy processing machinery

• Medical and pharmaceutical equipment

A4-80