S-91255A563 1/4"-28 x 1 1/2" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with Black-Oxide finish, ideal for harsh industrial environments.
• Superior tensile strength (120,000 psi) and Rockwell C39 hardness for reliable, long-lasting fastening under high stress.
• Precise Class 3A thread fit ensures tight, secure connections with minimal risk of loosening.
• Fully threaded design provides maximum grip and load distribution along the entire length.
• Hex drive (5/32") allows for easy installation and high torque application without slipping.
• Fine UNF thread (1/4"-28) offers enhanced vibration resistance and superior holding power.
• Compliance with ASME, ASTM, RoHS 3, and REACH guarantees safety, quality, and environmental standards.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel rounded head hex screw is engineered to address critical industrial challenges, such as vibration-induced loosening and corrosion in demanding applications. The Class 3A UNF fine thread provides exceptional clamping force and stability, making it ideal for precision machinery, automotive assemblies, and electronic enclosures where reliability is paramount. The fully threaded right-hand design ensures uniform stress distribution, reducing the risk of fatigue failure. With a high tensile strength of 120,000 psi and robust Rockwell C39 hardness, it delivers consistent performance in high-load scenarios, while the hex drive facilitates quick, secure installation with standard tools, minimizing downtime.

Specification Summary & Compliance

This screw features precise Class 3A thread fit per UNF standards, with dimensions including a 1/4"-28 fine thread, 1 1/2" length, and 5/32" hex drive. It meets ASME B18.3 and ASTM F835 specifications for quality and performance, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and industrial reliability.