Precision-Engineered A4-80 Stainless Steel Hex Nuts

A4-80 Hex Nuts Information, Composition & Properties

A4-80 stainless steel is a high-tensile, acid-resistant grade of austenitic stainless steel, primarily based on the 316 or 316L alloy specification. The designation A4 identifies it as a molybdenum-bearing austenitic steel, while the 80 signifies a minimum tensile strength of 800 MPa, achieved through rigorous cold working. This combination of chemical stability and mechanical power makes A4-80 hex nuts significantly stronger than standard A4-70 fasteners, providing the necessary load-bearing capacity for safety-critical assemblies in harsh environments.

Composition:

The chemical profile of A4-80 is defined by a high chromium content (16-18.5%), nickel (10-14%), and the essential addition of molybdenum (2-3%). Molybdenum is the key element that distinguishes A4 from A2 grades, providing enhanced resistance to pitting and crevice corrosion in chloride-rich atmospheres. The alloy also contains controlled amounts of manganese, silicon, and low carbon levels to ensure excellent stability and durability.

Properties:

• High Tensile Strength: With a minimum tensile strength of 800 MPa and a 0.2% proof stress of approximately 600 MPa, these nuts are engineered for high-load applications.
• Superior Corrosion Resistance: The molybdenum content offers exceptional protection against saltwater, industrial acids, and halogenated media, making them truly marine-grade.
• Temperature Versatility: A4-80 retains excellent toughness and structural integrity across a wide temperature spectrum, including cryogenic conditions and elevated service temperatures.
• Non-Magnetic Nature: In its annealed state, the material is non-magnetic, though it may exhibit low magnetic permeability after the cold-working process used to reach the 800 MPa strength rating.

Why A4-80 is ideal for Hex Nuts:

The use of A4-80 for hex nuts ensures that the internal threads can withstand high tightening torques and maintain a secure clamp load without stripping or failing under stress. These components are essential for industries such as maritime engineering, chemical processing, and offshore oil and gas, where fasteners must resist both extreme mechanical forces and aggressive corrosive agents to prevent catastrophic failure.

At West Special Fasteners, we take pride in every A4-80 Hex Nut we produce, no matter the application.

99% on-time delivery

At West Special Fasteners, we deliver precision-engineered fasteners with a proven 99% on-time delivery record, ensuring your projects stay on schedule. With lead times as short as 4 weeks for full-service orders, we provide unmatched reliability for industries where timing is critical.

• Minimise delays – Receive your special fasteners exactly when needed, helping you avoid costly project interruptions.
• Support critical operations – Our dependable delivery is essential for sectors like defence, offshore, and renewables, where timing is non-negotiable.
• Boost project efficiency – Reliable deliveries streamline your workflow, allowing you to focus on execution without supply chain concerns.
• Maintain your reputation – Trust in our punctuality to ensure your commitments to your clients are met, every time.
• Transparent communication – Realistic timelines and proactive updates at every stage.
• Efficient production – Our advanced facilities and streamlined processes enable us to deliver on time, even for complex and bespoke projects.

Our ability to always deliver on time sets us apart in the fastener industry. While with many competitors you can face frequent delays, we ensure your orders are delivered with precision and professionalism – backed by our fully traceable production process and industry-leading expertise.