S-91251A418 1"-14 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 in high-stress industrial environments, reducing the risk of fastener failure.
• Precision Class 3A fine UNRF threads provide superior fit and vibration resistance, minimizing loosening in critical assemblies.
• Black-oxide surface treatment on alloy steel offers enhanced corrosion resistance, extending service life in harsh operating conditions.
• Standard hex socket head with 3/4" drive allows for easy installation and high torque application in confined spaces.
• Full threading along the 2 3/4" length ensures uniform load distribution and versatile fastening depth for various applications.
• Rockwell C37 hardness maintains durability and wear resistance under repeated use and heavy loads.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material quality and environmental safety for global industrial standards.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address common challenges in heavy-duty mechanical and industrial assemblies. Its 1"-14 UNRF fine thread with Class 3A fit ensures precise alignment and secure fastening, reducing the risk of thread stripping and vibration-induced failures in machinery, automotive, and construction equipment. The corrosion-resistant black-oxide finish protects against rust and degradation in humid or chemically aggressive environments, while the high tensile strength and Rockwell C37 hardness provide long-term reliability under dynamic loads. Ideal for applications requiring hex drive accessibility and fully threaded engagement, this screw enhances assembly efficiency and structural integrity in demanding settings.

Specification Summary & Compliance

This socket head cap screw features a 1"-14 UNRF fine thread with Class 3A tolerance for precise fit, a 2 3/4" length, and is manufactured from alloy steel with a black-oxide surface treatment. It meets ASTM A574 specifications for high-strength fasteners and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material consistency.