S-91259A509 10-24 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength – With 140,000 psi tensile strength, this shoulder screw withstands high-stress applications, reducing the risk of fastener failure and maintenance downtime.
• Superior Corrosion Resistance – The black oxide finish provides a durable protective layer, extending service life in harsh industrial environments.
• Precision Thread Fit – Class 3A thread fit ensures tight, secure fastening with minimal backlash, ideal for assemblies requiring high accuracy.
• Enhanced Grip & Handling – Knurled head texture offers improved manual grip during installation, while the hex drive allows for efficient torque application with standard tools.
• High Hardness & Durability – Rockwell C32 hardness ensures the screw maintains its shape and performance under repetitive loads and vibration.
• Broad Industrial Compliance – Meets ASME B18.3, RoHS 3, and REACH standards, ensuring reliability and environmental safety for global supply chains.
• Optimized Shoulder Design – The precise shoulder diameter and length provide stable alignment for rotating components, reducing wear and misalignment in machinery.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address common challenges in precision assembly and rotating machinery. The 10-24 UNC coarse thread and Class 3A fit deliver secure, vibration-resistant fastening, critical in automotive, aerospace, and industrial equipment where loosening can lead to operational failures. The black oxide finish enhances corrosion resistance, making it suitable for environments exposed to moisture or chemicals. With a knurled socket head and hex drive, installation is streamlined, reducing assembly time. The shoulder acts as a precise pivot or spacer, ensuring accurate alignment in linkages, bearings, and gears, thereby minimizing wear and extending the lifespan of mechanical systems.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread tolerance for precise fit, with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005". It conforms to ASME B18.3 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it meets industry standards for performance and environmental safety.