S-91251A403 1 1/4"-12 x 2 3/4" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength (170,000 psi) ensures reliable performance in high-stress industrial applications, reducing failure risks.
• Black-oxide alloy steel construction provides enhanced corrosion resistance and durability in demanding environments.
• 7/8" hex drive design allows for secure, high-torque installation with standard tools, improving assembly efficiency.
• Fine UNF thread with Class 2A fit offers precise engagement and vibration resistance in critical assemblies.
• Fully threaded shank enables consistent clamping force along the entire length for uniform load distribution.
• Rockwell C37 hardness maintains structural integrity under heavy loads, extending service life.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees material quality and environmental safety for global supply chains.

Professional Applications & Engineering Value

This 1 1/4"-12 UNF socket head cap screw is engineered to address common industrial challenges such as vibration loosening and material fatigue. The black-oxide alloy steel offers superior protection against rust and wear, making it ideal for machinery, automotive, and heavy equipment applications. Its fine thread design ensures tight, secure fastening in high-vibration settings, while the fully threaded rod provides uniform stress distribution. With a 170,000 psi tensile strength and Rockwell C37 hardness, it delivers reliable performance in structural and load-bearing assemblies, reducing maintenance needs and downtime.

Specification Summary & Compliance

This screw adheres to Class 2A thread fit for precise dimensional accuracy and features a UNF fine thread (1 1/4"-12). It complies with ASTM A574 manufacturing standards, ensuring consistent quality and performance. Additionally, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious industrial use.