S-91255A381 5/16"-24 x 3/4" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating, extending service life in demanding industrial environments.
• Superior tensile strength of 120,000 psi ensures reliable performance under high-stress applications without failure.
• Precision Class 3A thread fit guarantees tight, secure fastening with minimal risk of loosening or vibration-induced issues.
• Hex drive design (3/16") allows for easy installation and high torque application, reducing assembly time and tool slippage.
• Fully threaded right-hand fine thread provides maximum grip and uniform load distribution across the entire length.
• Hardened to Rockwell C39 for excellent wear resistance and durability in repetitive or high-impact use.
• Compliant with major industry standards, including ASME B18.3 and ASTM F835, ensuring consistent quality and safety.

Professional Applications & Engineering Value

This 5/16"-24 UNF Class 3A black-oxide alloy steel rounded head hex screw is engineered to address critical challenges in industrial assembly, such as vibration resistance and environmental exposure. The black-oxide surface treatment provides a protective layer against rust and corrosion, making it ideal for machinery, automotive, and outdoor equipment where moisture or chemicals are present. With a fine thread spacing and Class 3A thread fit, it delivers superior clamping force and minimizes the risk of thread stripping in precision components. The hex drive ensures efficient torque transmission, reducing installation errors and enhancing productivity in high-volume manufacturing. Fully threaded and made from high-strength alloy steel, this screw offers reliable performance in applications requiring repeated disassembly and reassembly, such as industrial controls and heavy-duty enclosures.

Specification Summary & Compliance

This screw features a 5/16"-24 UNF fine thread with Class 3A tolerance for precise fit and consistent performance. It meets ASME B18.3 and ASTM F835 specifications, ensuring dimensional accuracy and mechanical reliability. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe usage in global markets.