S-92981A798 M8 ASTM A108 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Durability & Corrosion Resistance: Black oxide finish provides reliable protection against rust and wear in demanding industrial environments.
• Superior Load-Bearing Capability: Alloy steel construction with 140,000 psi tensile strength ensures high resistance to shear and tensile forces.
• Precise Component Alignment: 140mm shoulder length with tight tolerances allows for accurate positioning and reduced assembly vibration.
• Secure Fastening with Consistent Thread Fit: Class 5g6g thread ensures reliable engagement and minimizes the risk of loosening under dynamic loads.
• Easy Installation & Removal: Hex socket drive with 5mm size and knurled head offers excellent grip and torque transmission for efficient maintenance.
• High Hardness for Long Service Life: Rockwell C32 hardness provides exceptional wear resistance, reducing replacement frequency and downtime.
• Compliance with Industry Standards: Meets ASTM A108, RoHS 3, and REACH regulations, ensuring safety and environmental responsibility in global supply chains.

Professional Applications & Engineering Value

This M8 shoulder screw is engineered to address critical alignment and load distribution challenges in precision machinery. The alloy steel material, combined with a black oxide finish, offers robust corrosion resistance, making it ideal for automotive assemblies, industrial robots, and conveyor systems where exposure to oils and moisture is common. The 140mm shoulder length with minimal tolerance variation ensures stable bearing surfaces, reducing misalignment and extending component life. With a Class 5g6g thread fit and coarse thread pitch, it facilitates quick assembly while maintaining high clamping force, minimizing the risk of joint failure in high-vibration applications. The hex drive and knurled head design further enhance installation efficiency, supporting streamlined production and maintenance workflows.

Specification Summary & Compliance

This shoulder screw adheres to precise dimensional standards, including a shoulder diameter tolerance of -0.072 to -0.01 mm and shoulder length tolerance of 0 to 0.25 mm, ensuring consistent performance in metric assemblies. The M8x1.25 coarse thread conforms to Class 5g6g fit for reliable engagement. Manufacturing and material specifications comply with ASTM A108, while environmental regulations such as RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) are fully met, guaranteeing safe and sustainable use.