S-91259A726 3/8"-16 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Load-Bearing Capacity – With 140,000 psi tensile strength and 84,000 psi minimum shear strength, this shoulder screw provides reliable performance in high-stress applications.
• Superior Corrosion Resistance – The black oxide finish protects against rust and wear, extending service life in harsh industrial environments.
• Precision Shoulder Fit – A 1/2" shoulder diameter with tight tolerances ensures accurate alignment and smooth rotational movement in assemblies.
• High-Strength Alloy Steel Construction – Made from alloy steel with Rockwell C32 hardness for durability and resistance to deformation under heavy loads.
• Easy Installation & Removal – The 1/4" hex drive and knurled head offer secure grip and efficient torque application with standard tools.
• Reliable Thread Engagement – 3/8"-16 UNC coarse thread with Class 3A fit provides strong, vibration-resistant fastening in various materials.
• Compliance with Industry Standards – Meets ASME B18.3, RoHS 3, and REACH regulations, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in machinery, automation, and precision equipment. The 3-1/2" shoulder length with minimal tolerance variation allows for exact positioning of components like gears, pulleys, and linkages, reducing wear and misalignment. The black oxide finish enhances corrosion resistance, making it suitable for environments exposed to moisture or chemicals. With a Class 3A thread fit and UNC coarse thread, it ensures quick assembly and high clamping force, minimizing loosening under dynamic loads. Ideal for industrial fasteners in automotive, aerospace, and manufacturing sectors, this screw delivers consistent performance where reliability and precision are paramount.

Specification Summary & Compliance

This shoulder screw features a 3/8"-16 UNC thread with Class 3A fit for precise engagement. The shoulder diameter is 1/2" with a tolerance of -0.004" to -0.002", and the shoulder length is 3-1/2" with a tolerance of -0.005" to 0.005", ensuring dimensional accuracy. It complies with ASME B18.3 specifications, RoHS 3 (2015/863/EU), and REACH (EC 1907/2006) standards, confirming adherence to safety and environmental guidelines.