S-91264A537 1/4"-20 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Superior tensile strength of 140,000 psi ensures reliable performance under high-stress conditions, reducing failure risks in demanding applications.
• Integrated nylon pellet thread locker provides secure, vibration-resistant fastening from -50° to 250°F, minimizing loosening in dynamic environments.
• Black oxide finish on alloy steel enhances corrosion resistance and durability, extending service life in harsh industrial settings.
• Precision Class 3A thread fit with UNC coarse threading offers easy assembly and consistent engagement, improving installation efficiency.
• Knurled socket head with 5/32" hex drive allows for high-torque application and secure grip, facilitating quick maintenance and adjustments.
• Rockwell C32 hardness ensures excellent wear resistance, maintaining dimensional stability and reducing replacement frequency.
• Compliance with ASME B18.3, RoHS 3, and REACH guarantees adherence to industry standards and environmental regulations, supporting safe and sustainable operations.

Professional Applications & Engineering Value

This 1/4-20 UNC shoulder screw is engineered to address critical challenges in industrial assembly, such as misalignment and vibration-induced loosening. The alloy steel construction with black oxide finish provides robust protection against corrosion and wear, making it ideal for machinery, automotive, and aerospace components where precision and reliability are paramount. The integrated nylon pellet thread locker ensures stable fastening across a wide temperature range (-50° to 250°F), preventing downtime in high-vibration environments. With a shoulder diameter of 5/16" and precise tolerances, it facilitates accurate positioning in linkages, pivots, and rotating assemblies, enhancing overall system integrity and reducing maintenance needs for B2B clients.

Specification Summary & Compliance

This shoulder screw features UNC coarse threads with a Class 3A thread fit for high precision, along with a shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005" to ensure consistent performance. It meets ASME B18.3 specifications under ASTM A574, and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible manufacturing and use in global industrial markets.