S-91251A393 5/16"-24 x 2 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Black-oxide finish on alloy steel provides enhanced corrosion resistance, extending service life in demanding industrial environments.
• Class 3A thread fit offers superior precision and tighter tolerances for secure, vibration-resistant assemblies.
• Partially threaded design allows for precise clamping force control and easier alignment in specific mounting scenarios.
• Hex socket drive with 1/4" drive size enables high-torque installation and removal, minimizing stripping and improving efficiency.
• Rockwell C37 hardness ensures excellent wear resistance and durability under repetitive loads.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material consistency and environmental safety for global supply chain integration.

Professional Applications & Engineering Value

This 5/16"-24 UNF socket head cap screw is engineered to address critical challenges in precision machinery, automotive assemblies, and heavy-duty equipment. The black-oxide alloy steel construction combats rust and wear in harsh conditions, while the fine thread spacing and Class 3A thread fit provide superior holding power against vibrations and dynamic loads. Its partially threaded shank design allows engineers to optimize grip range and reduce stress concentration, making it ideal for applications requiring exact clamping lengths. With a Rockwell C37 hardness and 170,000 psi tensile strength, it ensures long-term reliability in high-stress environments, from aerospace components to industrial automation systems.

Specification Summary & Compliance

This fastener adheres to Class 3A thread fit for precise dimensional accuracy under the UNF (Unified National Fine) standard. It meets the ASTM A574 specification for high-strength alloy steel socket head cap screws, ensuring consistent manufacturing quality. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious and regulated industries.