S-91251A464 1/4"-28 x 2 3/4" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish extends service life in harsh industrial environments.
• Precise Class 3A thread fit guarantees secure, vibration-resistant connections for critical assemblies.
• Fine UNF threads provide enhanced grip and load distribution compared to coarse threads.
• Partially threaded design allows for optimal clamping force control and easier alignment in applications.
• Hex socket drive enables high-torque installation with standard tools, minimizing stripping and improving efficiency.
• Compliance with ASTM A574 ensures consistent quality and material integrity for demanding engineering uses.

Professional Applications & Engineering Value

Engineered for high-strength industrial applications, these black-oxide alloy steel socket head cap screws address common challenges like vibration loosening and corrosion in machinery, automotive, and aerospace sectors. The fine UNF threads and Class 3A fit deliver superior clamping force and fatigue resistance, while the partial threading simplifies assembly in components requiring precise unthreaded shank sections. With a Rockwell C37 hardness and robust ASTM A574 compliance, they offer long-term reliability in environments demanding corrosion resistance and repeated load cycles, reducing maintenance needs and downtime.

Specification Summary & Compliance

This screw features a 1/4"-28 UNF thread with Class 3A fit for tight tolerances, a 2 3/4" length, and partial threading from a minimum of 1". It meets ASTM A574 specifications for material and manufacturing, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and suitability for global industrial use.