S-91355A177 1/4"-20 x 5/16" Steel Flanged Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance in high-stress industrial environments, reducing the risk of fastener failure.
• Black-Oxide coating on alloy steel provides enhanced corrosion resistance and a durable finish, extending service life in demanding conditions.
• Class 3A thread fit offers superior precision and tight tolerances for secure, vibration-resistant assemblies in critical applications.
• Integrated flange design eliminates the need for separate washers, simplifying installation and providing a larger bearing surface for improved load distribution.
• Hex drive (5/32") allows for high-torque application with common tools, ensuring quick and secure fastening without slippage.
• Fully threaded coarse UNC pattern enables faster installation and stronger holding power in a variety of materials, from metal to composites.
• RoHS 3 and REACH compliance guarantees adherence to environmental and safety regulations, making them suitable for global industrial supply chains.

Professional Applications & Engineering Value

This 1/4-20 UNC Class 3A Rounded Head Screw is engineered to address common industrial challenges such as vibration loosening and corrosion in heavy machinery, automotive assemblies, and structural frameworks. The Black-Oxide Alloy Steel construction, combined with a Rockwell C32 hardness rating, ensures durability against wear and environmental exposure. The flanged design and coarse thread provide excellent clamp load retention and rapid installation, reducing downtime in production lines. Ideal for applications requiring high tensile strength and reliable fastening, these screws meet the demands of industrial screw applications where precision and compliance with standards like RoHS and REACH are critical for operational safety and efficiency.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with Class 3A fit for precise tolerances, ensuring consistent performance in threaded assemblies. It adheres to standard UNC thread specifications and is manufactured from alloy steel with a Black-Oxide surface treatment for added protection. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally conscious and regulated industrial sectors without hazardous substances.