A2-70 stainless steel flange nut

螺栓與螺帽的鎖緊與開口採用非標準設計，搭配
使用非標準工具來解決打開和緊固問題。一般而言，其他
wrenches cannot be inserted. In the appearance design of nuts and bolts, non-standard slotting,
開口或五角、七角、九角或客製化對應槽工具
起到了很好的防盜效果

冷镦加工是一种少切削或无切削的压力加工新工艺
金屬。它是一種利用金屬在下列因素作用下產生塑性變形的加工方法
外力作用下，在模具的幫助下，重新分配和轉移金屬的體積，以形成
所需的零件或坯料。冷镦工艺最适合生产标准的
螺栓、螺絲、螺帽、鉚釘和銷等緊固件

A2-70 Stainless Steel Flange 堅果 – 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.