S-91264A535 1/4"-20 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced vibration resistance with integrated nylon locking pellet that maintains secure fastening from -50° to 250°F, preventing loosening in demanding applications
• Superior load-bearing capability with 140,000 psi tensile strength and 84,000 psi shear strength, ensuring reliable performance under high-stress conditions
• Precise component alignment through standardized shoulder diameter and length with tight tolerances, providing accurate positioning in assemblies
• Exceptional corrosion protection with black oxide finish on alloy steel, extending service life in harsh industrial environments
• Reliable thread engagement with Class 3A UNC coarse threads offering superior fit and consistent torque performance
• Easy installation and removal with hex socket drive (5/32") and knurled head texture, providing secure tool grip and efficient maintenance
• Comprehensive regulatory compliance meeting ASME B18.3, RoHS 3, and REACH standards for global industrial applications

Professional Applications & Engineering Value

This 1/4"-20 UNC shoulder screw delivers critical engineering solutions for industrial applications where vibration resistance and precise alignment are paramount. The alloy steel construction with black oxide finish provides exceptional durability against corrosion and wear, while the integrated nylon locking pellet technology ensures maintained clamp force in high-vibration environments such as machinery, automotive assemblies, and precision equipment. The Class 3A thread fit guarantees precise engagement with mating components, reducing the risk of cross-threading and ensuring consistent torque values. The standardized shoulder diameter and length with tight tolerances enable accurate positioning of rotating components, making these socket head shoulder screws ideal for applications requiring both structural support and rotational freedom.

Specification Summary & Compliance

This shoulder screw features precision Class 3A UNC threads with 1/4"-20 coarse thread spacing and 7/16" thread length. The shoulder maintains tight diameter tolerance (-0.004" to -0.002") and length tolerance (-0.005" to 0.005") for precise fitment. Manufactured to ASME B18.3 specifications using ASTM A574 alloy steel with Rockwell C32 hardness. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets.