S-91251A550 1/4"-20 x 2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under extreme loads, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the black-oxide finish extends service life and maintains integrity in harsh or humid industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening over time.
• Partially threaded design offers optimal grip and clamping force where needed, allowing for better control in positioning and alignment.
• High hardness (Rockwell C37) enhances wear resistance and durability, making it suitable for high-stress mechanical systems.
• Hex socket drive (3/16") enables easy installation with standard tools, reducing assembly time and improving efficiency in tight spaces.
• Compliance with RoHS 3 and REACH ensures environmental safety and meets international regulatory standards for industrial use.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address common challenges in heavy-duty industrial settings, such as vibration-induced loosening and corrosion. The UNRC coarse thread and Class 3A fit provide excellent holding power in materials like steel and aluminum, while the partial threading allows for precise clamping without compromising strength. Ideal for machinery, automotive, and construction applications, its 170,000 psi tensile strength and Rockwell C37 hardness ensure long-term reliability under dynamic loads. The black-oxide surface treatment further enhances corrosion resistance, making it a dependable choice for environments exposed to moisture or chemicals, thereby reducing maintenance costs and downtime.

Specification Summary & Compliance

This socket head cap screw features a 1/4"-20 thread size with UNRC coarse threading and Class 3A thread fit for high precision. It meets ASTM A574 specifications, ensuring consistent quality and performance. The product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), supporting environmentally responsible manufacturing and use in various industrial sectors.