A2-70 Hex Head Bolt

A2-70 Hex Head Bolt About

An A2-70 hex head bolt is a high-performance, corrosion-resistant metric fastener manufactured from 304-grade (18/8) austenitic stainless steel that has been cold-worked to achieve a minimum tensile strength of 700 MPa (N/mm). The "A2" designation represents its standard 304 chemical composition, while the "70" specifies its high-strength classification. Featuring a six-sided external drive head designed for high-torque installations using a standard spanner or socket wrench, this fastener is widely utilized across heavy construction, automotive, marine, and industrial engineering applications.

Technical Specifications

• Material Composition: Grade 304 Austenitic Stainless Steel (typically 18% Chromium, 8% Nickel).

• Mechanical Strength Class: Class 70.

• Minimum Tensile Strength: 700 MPa / 700 N/mm.

• Proof Load Capacity: 700 Newtons per square millimetre.

• Magnetic Properties: Typically, non-magnetic or almost non-magnetic due to the austenitic structure.

• Standard Conformity: Commonly manufactured to DIN 933 (fully threaded), DIN 931 (partially threaded), or ISO 4014 / 4017 international standards.

• Size Range Availability: Commonly stocked from M2 up to M100 diameters with customizable thread pitches.
  
  

Key Features & Product Benefits

• Superior Rust Resistance: High chromium content forms a self-healing oxide layer, ensuring long-lasting performance in humid, damp, or harsh weather conditions without rusting.

• High Torque Delivery: The classic hexagonal head design eliminates the risk of tool slippage, allowing operators to apply maximum tightening force safely during assembly.

• Thermal & Acid Proof Stability: Retains high physical integrity and resists distortion or degradation across varied operating temperatures and chemical-heavy exposure levels.

• Hygienic Cleanliness: Features an easy-to-clean bright finish that prevents bacterial buildup, making it ideal for specialized environments.
  
  

Primary Applications

• Civil Infrastructure: Securely fastening steel bridges, architectural framework joints, and concrete structural columns.

• Industrial & Heavy Equipment: Securing pipeline flanges, mining platforms, vehicle engine components, and wind turbine bases.

• Marine & Energy Sectors: Assembled in sub-sea, near-shore, or solar farm installations where moisture and oxidization are constantly present.

• Commercial Machinery & DIY: Extensively deployed in food processing plants, catering setups, medical devices, automotive panels, and high-end home restoration projects.