S-91355A183 1/4"-20 x 3" Steel Flanged Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional durability with Black-Oxide Alloy Steel construction providing superior corrosion resistance and long service life in harsh industrial environments.
• High load-bearing capacity thanks to 120,000 psi tensile strength and Rockwell C32 hardness, ensuring reliable performance under heavy mechanical stress.
• Precise, secure fastening with Class 3A thread fit and UNC coarse spacing, reducing cross-threading risks and enabling quick, stable installations.
• Enhanced grip and torque application via the 5/32" hex drive and flanged design, preventing slipping and distributing clamp load effectively.
• Full-thread engagement along the 3" length for maximum holding power and vibration resistance in demanding assemblies.
• Wide-rounded button head profile offers a low-profile, aesthetically clean finish while minimizing surface damage.
• Compliance with global standards including RoHS 3 and REACH, ensuring safe, environmentally responsible use in regulated industries.

Professional Applications & Engineering Value

This 1/4"-20 x 3" Black-Oxide Alloy Steel Rounded Head Screw is engineered to address critical challenges in heavy-duty industrial applications, such as machinery assembly, automotive frameworks, and construction equipment. The Black-Oxide surface treatment enhances corrosion resistance, reducing maintenance needs in humid or abrasive settings. With a fully threaded UNC coarse spacing and Class 3A thread fit, it ensures rapid, precise installation without compromising strength, ideal for high-vibration environments where loosening is a concern. The flanged design and hex drive simplify torque application, providing consistent clamp force and eliminating the need for separate washers. By integrating high tensile strength and compliance with RoHS and REACH, this screw delivers reliable, long-term performance while meeting stringent industry regulations for safety and sustainability.

Specification Summary & Compliance

This screw adheres to UNC thread standards with a Class 3A thread fit for precise dimensional accuracy and tight tolerances. It features a coarse thread spacing, right-hand thread direction, and fully threaded design along the 3" length. Manufactured from Alloy Steel with a Black-Oxide finish, it complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and suitability for global industrial use.