304 - Stainless steel - Hexagon socket cap screw

Why Choose 304 Stainless Socket Screws?

When engineers need a fastener that won't rust in rain or humidity, Grade 304 (A2) is the most cost-effective solution. While not suitable for direct salt-water immersion (where 316 is needed), 304 performs exceptionally well in standard urban and industrial environments. The socket cap design allows these screws to be installed in tight spaces or counter-bored holes, providing a flush, snag-free surface that is both functional and visually appealing.

Material Specifications: A2-70

Chemical Composition: Grade 304 is an austenitic stainless steel containing 18% Chromium and 8% Nickel. This "18/8" chemistry creates a self-repairing oxide layer on the surface. If the screw is scratched during installation, the chromium reacts with oxygen to heal the protective layer instantly, preventing rust from taking hold. Mechanical Strength (Class 70): Our 304 socket screws are supplied in the cold-worked condition, known as Class 70. This means they have a minimum tensile strength of 700 N/mm² and a yield strength of 450 N/mm². While not as strong as high-tensile carbon steel (Grade 12.9), A2-70 provides ample strength for most non-critical structural joints, panel mounting, and machinery covers.

Quality Assurance

We ensure that every batch of A2 fasteners meets strict international standards. An EN 10204 3.1 Material Certificate verifying the chemical composition is available upon request. Please note that third-party inspection services require an additional fee.

Common Applications

The clean finish and durability of 304 plain head socket screws make them popular in:

• Food & Beverage: Machinery assembly where wash-down procedures are common (the plain head is easier to wipe clean).
• Architectural Fittings: Glass balustrades, handrails, and visible interior design elements.
• Automotive Styling: Engine bay dress-up kits and license plate fasteners.
• Consumer Electronics: High-end audio equipment and appliance casings.

Frequently Asked Questions

Why are these screws non-magnetic?

Austenitic stainless steel (304) is non-magnetic in its raw state. However, do not be surprised if the screws exhibit slight magnetism. The cold-forging process used to form the head and roll the threads changes the grain structure slightly, introducing a small amount of magnetism. This does not affect corrosion resistance.

Can I use A2 stainless screws with aluminum?

Yes, but be aware of galvanic corrosion. Stainless steel and aluminum are dissimilar metals. In dry environments, this is fine. In wet or marine environments, the aluminum will sacrifice itself and corrode around the screw. Using a nylon washer or anti-seize paste can help separate the metals.

What happens if I over-torque small socket screws?

Care must be taken with smaller sizes (M3 and below). Stainless steel is softer than hardened carbon steel. If you apply excessive torque to a small A2 stainless screw, you risk "rounding out" the internal hex drive, making it impossible to tighten or remove. Always use a high-quality Allen key and appropriate torque settings for these smaller diameters.