Precision-Engineered A4-80 Stainless Steel Hex Bolts

A4-80 Hex Bolts Information, Composition & Properties

A4-80 stainless steel is a high-tensile, acid-resistant austenitic grade specifically engineered for fasteners that require a combination of exceptional mechanical strength and superior corrosion resistance. The designation A4 identifies it as part of the molybdenum-stabilised 316 stainless steel family, while the 80 denotes a minimum tensile strength of 800 MPa, achieved through a precise cold-working process. This makes A4-80 hex bolts significantly stronger than standard A4-70 or A2-70 fasteners, allowing them to support heavier loads in safety-critical industrial and marine applications.

Composition:

The chemical profile of A4-80 is defined by its high chromium (16-18.5%), nickel (10-14%), and molybdenum (2-3%) content. The chromium provides the foundational passivity for corrosion resistance, while the high nickel content ensures structural stability and toughness. The addition of molybdenum is critical, as it provides specific protection against pitting and crevice corrosion in chloride-rich environments. The low carbon content (typically ≤0.08%) helps maintain the integrity of the alloy during manufacturing.

Properties:

• High Mechanical Strength: With a minimum tensile strength of 800 MPa and a yield strength of approximately 600 MPa, these bolts offer performance comparable to grade 8.8 carbon steel but with integrated corrosion protection.
• Superior Corrosion Resistance: The molybdenum-bearing structure provides excellent resistance to marine atmospheres, salts, and various industrial acids, making it ideal for offshore and chemical processing.
• Cryogenic Toughness: As an austenitic alloy, A4-80 retains excellent ductility and impact strength even at extremely low temperatures, unlike many carbon steels that become brittle.
• Non-Magnetic Nature: In its annealed state, the material is non-magnetic, though the cold-working process used to achieve the 800 MPa strength may introduce a slight magnetic permeability.

At West Special Fasteners, we take pride in every A4-80 Hex Bolt 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.