S-90484A542 1/4"-20 x 1" ASME B18.3, ASTM F835 Tamper-Resistant Hex-Drive Steel Button Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide coating, ideal for harsh industrial environments and long-term reliability.
• Enhanced tamper-proof security via the tamper-resistant hex drive, preventing unauthorized access in public or sensitive equipment.
• High tensile strength of 130,000 psi ensures dependable performance under heavy loads and mechanical stress.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies in critical applications.
• Fully threaded design allows for maximum grip and uniform load distribution along the entire fastener length.
• Durable alloy steel construction with Rockwell C39 hardness offers excellent wear resistance and repeated use capability.
• Compliance with ASME B18.3, RoHS 3, and REACH guarantees adherence to industry standards and environmental safety regulations.

Professional Applications & Engineering Value

This 1/4-20 UNC black-oxide alloy steel rounded head screw is engineered to address common industrial challenges such as tampering, corrosion, and mechanical failure. The tamper-resistant hex drive enhances security in public infrastructure, machinery, and electronic enclosures, while the black-oxide surface treatment provides a robust barrier against rust and environmental degradation. With a coarse thread spacing and fully threaded design, it ensures quick installation and reliable holding power in materials like metal, wood, and composites. Ideal for heavy-duty applications including automotive assemblies, construction frameworks, and industrial equipment, this screw delivers consistent performance, reduced maintenance, and extended service life under demanding conditions.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC thread size with Class 3A thread fit for high precision and tight tolerances. It is manufactured to meet ASME B18.3 specifications, ensuring dimensional accuracy and performance reliability. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), it adheres to environmental and safety standards, making it suitable for global supply chains and regulated industries.