S-91255A844 3/8"-24 x 2 1/2" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the Black-Oxide finish on Alloy Steel, extending service life in harsh industrial environments.
• Precise Class 3A thread fit provides a tighter, more secure connection, minimizing loosening under vibration and improving assembly integrity.
• High Rockwell C39 hardness offers excellent wear resistance, maintaining thread integrity and dimensional stability over repeated use.
• Easy installation and removal with a 7/32" hex drive and rounded button head design, reducing assembly time and tool slippage.
• Fully threaded shank allows for maximum grip and adjustability along the entire length, ideal for varying material thicknesses.
• Compliance with major standards including ASME B18.3 and ASTM F835, ensuring consistent quality and reliability for engineering applications.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Rounded Head Screw is engineered to address common industrial challenges such as vibration-induced loosening and corrosion in demanding environments. The Class 3A UNF fine threading ensures a precise, secure fit that resists back-off, making it ideal for machinery, automotive assemblies, and precision equipment where reliability is critical. The high tensile strength and Rockwell C39 hardness provide durability against mechanical stresses, while the Black-Oxide surface treatment enhances corrosion resistance without sacrificing dimensional accuracy. Its rounded head with hex drive facilitates quick installation in tight spaces, reducing labor costs and improving efficiency in production lines. Suitable for applications requiring fine thread screws with consistent performance under heavy loads.

Specification Summary & Compliance

This screw features a 3/8"-24 UNF fine thread with Class 3A fit for high precision, fully threaded for uniform engagement. It meets ASME B18.3 and ASTM F835 specifications, ensuring dimensional accuracy and mechanical properties. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it is free from hazardous substances, supporting safe and sustainable industrial use.