S-91259A138 3/4"-10 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Load Distribution: The 1" shoulder diameter and 3" shoulder length provide a precise bearing surface, reducing wear on components and ensuring accurate alignment in assemblies.
• Superior Tensile and Shear Performance: With a tensile strength of 140,000 psi and minimum shear strength of 84,000 psi, this screw offers reliable fastening under high-stress conditions, minimizing the risk of failure.
• Precise Thread Engagement: Class 3A thread fit ensures tight tolerances and secure connections, reducing the likelihood of loosening in vibrating environments.
• Durable Corrosion Resistance: The black oxide finish on alloy steel enhances corrosion protection, extending service life in harsh industrial settings.
• Easy Installation and Removal: The knurled socket head with 1/2" hex drive allows for high-torque application without slippage, speeding up assembly and maintenance processes.
• High Hardness for Longevity: Rockwell C32 hardness provides excellent resistance to deformation and wear, ensuring consistent performance over repeated use.
• Compliance with Industry Standards: Meets ASME B18.3, RoHS 3, and REACH regulations, guaranteeing safety, environmental responsibility, and interoperability in global applications.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in precision machinery, such as misalignment and component wear. The UNC coarse threads and Class 3A fit ensure rapid assembly with minimal play, ideal for high-vibration environments like automotive or aerospace systems. The black oxide finish adds a layer of corrosion resistance, prolonging life in humid or chemically exposed settings. With a robust shoulder diameter of 1" and length of 3", it acts as a reliable pivot or spacer, reducing stress concentrations and enhancing overall structural integrity. Commonly used in jigs, fixtures, and rotating assemblies, this socket head shoulder screw delivers consistent performance, backed by ASME B18.3 compliance, making it a trusted choice for engineers seeking durability and precision in industrial fastening solutions.

Specification Summary & Compliance

This shoulder screw features precise dimensions, including a shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005", ensuring high accuracy for Class 3A thread fit and standard shoulder fit. It adheres to ASME B18.3 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious and safe industrial use.