S-91255A532 1/4"-20 x 4" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, extending service life in demanding industrial environments.
• Exceptional tensile strength of 120,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure.
• Precise Class 3A thread fit provides consistent engagement and vibration resistance, minimizing loosening in critical assemblies.
• Hex drive design (5/32") allows for high-torque installation and easy access in confined spaces, speeding up assembly processes.
• Fully threaded UNC coarse spacing offers quick installation and strong holding power across the entire 4" length.
• High hardness (Rockwell C39) enhances durability and wear resistance, maintaining thread integrity through repeated use.
• Compliance with ASME B18.3 and ASTM F835 guarantees consistent quality and interchangeability for engineering and maintenance projects.

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 heavy machinery, automotive, and construction applications. The fully threaded UNC coarse thread with Class 3A fit ensures rapid assembly and secure fastening in materials where coarse spacing is preferred for quicker engagement and debris resistance. The hex drive and rounded (button) head design provide a low-profile, flush finish while allowing high torque application, making it ideal for assemblies requiring both aesthetic cleanliness and structural reliability. Its high tensile strength and hardened material resist deformation under load, reducing maintenance cycles and improving operational safety in dynamic environments.

Specification Summary & Compliance

This screw adheres to precise dimensional standards with a Class 3A thread fit and UNC coarse thread specifications, ensuring tight tolerances for reliable performance. It meets ASME B18.3 and ASTM F835 manufacturing standards, and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for global industrial use without hazardous substances.