S-91251A394 5/16"-24 x 2 3/4" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Superior tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure.
• Black-oxide coating on alloy steel provides enhanced corrosion resistance, extending service life in demanding industrial environments.
• Class 3A thread fit offers precise, tight tolerances for secure fastening and vibration resistance in critical assemblies.
• Fine UNRF thread spacing delivers improved load distribution and superior holding power compared to coarse threads.
• Partially threaded design allows for controlled clamping force and easier alignment in applications requiring specific grip lengths.
• Hex socket drive enables high-torque installation with standard tools, minimizing stripping and ensuring efficient assembly.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material consistency, environmental safety, and global regulatory acceptance.

Professional Applications & Engineering Value

This 5/16"-24 UNRF Socket Head Cap Screw is engineered to address common industrial challenges such as joint integrity and environmental durability. The black-oxide alloy steel construction combats rust and wear, making it ideal for machinery, automotive, and heavy equipment where exposure to moisture and chemicals is frequent. Its fine thread spacing and Class 3A fit provide exceptional vibration resistance, preventing loosening in dynamic applications. With a Rockwell C37 hardness and 170,000 psi tensile strength, it withstands extreme loads without deformation, ensuring long-term reliability in high-strength socket screw assemblies. The partially threaded rod allows precise engagement, reducing stress concentration and improving fatigue life in critical connections.

Specification Summary & Compliance

This screw adheres to Class 3A thread fit for high precision and UNRF fine thread standards with a diameter of 0.3125". It meets ASTM A574 specifications for alloy steel socket head cap screws, ensuring consistent manufacturing quality. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), it supports environmental and safety regulations for industrial use.