S-91259A360 1 1/8"-7 ASME B18.3 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 reliably handles high-stress applications without failure.
• Precision Thread Fit for Secure Fastening – Class 3A thread fit ensures tight, vibration-resistant connections, reducing the risk of loosening in dynamic environments.
• Enhanced Corrosion & Wear Resistance – The black oxide finish on alloy steel provides durable protection against rust and abrasion, extending service life in harsh conditions.
• Optimized for Easy Installation & Grip – Knurled head and 7/8" hex drive offer superior torque application and handling, even in confined or greasy workspaces.
• Rigorous Quality & Compliance Assurance – Manufactured to ASME B18.3 standards and compliant with RoHS 3 and REACH, ensuring safety and environmental responsibility.
• Accurate Shoulder Dimensions for Alignment – Tight shoulder diameter and length tolerances provide consistent positioning and support for moving parts.
• Coarse Threads for Quick Assembly – 1 1/8"-7 UNC coarse threads enable faster installation and are less prone to clogging in dirty or high-debris settings.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in heavy machinery, automation systems, and precision equipment. The black oxide finish combats corrosion in humid or chemically exposed environments, while the Class 3A thread fit and coarse UNC threads ensure reliable, vibration-resistant fastening that withstands cyclic loads. The knurled socket head and generous hex drive size facilitate secure tool engagement, reducing installation time and preventing stripping. Ideal for pivots, axles, and guides, this screw’s precision shoulder maintains alignment in assemblies, minimizing wear and downtime. Its compliance with ASME B18.3 and environmental regulations makes it a trusted choice for OEMs and maintenance teams seeking durability and regulatory adherence.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit and UNC coarse thread standards, with precise shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005". It meets ASME B18.3 manufacturing specifications and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring it is free of hazardous substances and suitable for global industrial use.