S-91259A413 8-32 ASME B18.3, ASTM A108 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 140,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Precision Class 3A thread fit provides superior engagement and vibration resistance, enhancing assembly integrity and longevity.
• Black oxide finish offers excellent corrosion resistance, extending service life in demanding industrial environments.
• Knurled socket head with hex drive allows for secure tool grip and easy installation, minimizing slippage and improving efficiency.
• 2" shoulder length with tight tolerances ensures accurate alignment and smooth rotation for pivots, gears, and other mechanical components.
• Alloy steel construction with Rockwell C32 hardness delivers outstanding durability and wear resistance, suitable for heavy-duty use.
• Compliance with major standards including ASME B18.3 and ASTM A108 guarantees consistent quality and interoperability in professional settings.

Professional Applications & Engineering Value

This 8-32 UNC shoulder screw is engineered to address critical challenges in precision assemblies, such as misalignment and component wear. The alloy steel material, combined with a black oxide finish, provides robust resistance to corrosion and mechanical stress, making it ideal for applications in machinery, automotive systems, and industrial equipment. The 2" shoulder length with minimal tolerances ensures exact positioning for rotating parts like bearings and linkages, reducing friction and maintenance needs. Its coarse thread and Class 3A fit enhance grip in high-vibration environments, while the socket head design with knurling facilitates quick, secure installation. By integrating these features, this fastener supports reliable, long-term performance in demanding engineering projects.

Specification Summary & Compliance

This shoulder screw adheres to precise dimensional standards, including a Class 3A thread fit for superior accuracy and a shoulder diameter tolerance of -0.004" to -0.002". It meets ASME B18.3 and ASTM A108 specifications, ensuring consistent manufacturing quality. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmental safety and regulatory requirements in industrial supply chains.