A2-70 stainless steel flange nut

The fastening and opening of bolts and nuts adopts non-standard design, and the matching
non-standard tools are used to solve the opening and fastening problems. In general, other
wrenches cannot be inserted. In the appearance design of nuts and bolts, non-standard slotting,
opening or pentagonal, heptagonal, nine-corner or custom-made corresponding groove tools
have played a very good anti-theft effect

Cold heading process is one of the new processes for pressure machining of less or no cutting
metal. It is a processing method that utilizes the plastic deformation of metal under the action of
external forces, and with the aid of molds, redistributes and transfers the volume of metal to form
the required parts or blanks. The cold heading process is most suitable for producing standard
fasteners such as bolts, screws, nuts, rivets, and pins.etc

A2-70 Stainless Steel Flange Nuts – Complete Overview

1. Definition & Purpose

An A2-70 flange nut is a stainless steel locking nut with an integrated wide circular flange at its base. It is designed to distribute clamping pressure, reduce surface damage, and resist loosening under vibration.

The “A2-70” designation specifies:

• A2: Austenitic stainless steel (Type 304 – 18% Cr, 8% Ni)

• 70: Minimum tensile strength of 700 MPa (with a proof load of 450 MPa)

2. Material Properties

• Corrosion Resistance: Excellent resistance to rust, water, and mild chemicals (suitable for outdoor, marine, and food-grade applications).

• Temperature Range: Typically performs well between -200°C to +400°C (varies based on environment).

• Magnetic Properties: Generally non-magnetic (but may become slightly magnetic after cold working).

3. Design Features

• Flange Type:

  • Flat Flange (Smooth): Standard load distribution.

  • Serrated Flange: Teeth on the underside grip the surface, preventing loosening from vibration.

• Thread Type: Metric (e.g., M6, M8, M10) or UNC/UNF (imperial).

• Finish: Typically natural mill finish (bright, uncoated stainless steel), but may also be dull polished or electropolished for specific uses.

6. Common Applications

• Automotive & Machinery: Engine components, exhaust systems, and vibrating equipment.

• Plumbing & HVAC: Piping, valves, and fluid systems.

• Marine & Offshore: Saltwater-resistant fastening.

8. Limitations

• Not for Extreme Chloride Exposure (e.g., constant saltwater submersion – A4-70 is better).

• Higher Cost than carbon steel or zinc-plated nuts.

• Limited High-Temp Use – May lose strength above 400°C.

Conclusion

The A2-70 stainless steel flange nut is a high-strength, corrosion-resistant fastener ideal for applications requiring vibration resistance, load distribution, and durability.