Class 8.8 fasteners are medium-carbon steel fasteners that have been quenched and tempered, offering a good balance of strength and toughness. The "8.8" classification refers to the material's performance according to the ISO metric standard, specifically indicating a tensile strength of 800 MPa and a yield strength of 640 MPa, which is 80% of the tensile strength.
Key Characteristics of Class 8.8 Fasteners:
Material Composition: Made from medium carbon steel, often with added alloys to improve hardening capabilities and strength.
Mechanical Properties: High tensile strength of 800 MPa and yield strength of 640 MPa, making them suitable for moderately demanding applications.
Heat Treatment: Quenched and tempered to achieve the desired mechanical properties, enhancing the fastener’s durability and load-bearing capacity.
Corrosion Resistance: Generally, these fasteners have limited corrosion resistance and are often zinc-plated or otherwise coated to improve their resistance to rust. They are not suitable for highly corrosive environments unless specifically coated.
Applications: Commonly used in general engineering, construction, automotive, and machinery applications where moderate levels of strength and hardness are required.
Identification: Typically marked with "8.8" on the head of bolts and screws, indicating their strength class for easy identification.
Magnetic Properties: Magnetic due to their steel composition.
Standards Compliance: They conform to various international standards, including ISO 898-1, ensuring reliability and consistency in mechanical properties.
Class 8.8 fasteners are popular for their balance of strength and cost-effectiveness, making them suitable for a wide range of non-critical to moderately critical structural and engineering applications.
