S-90429A129 1/4"-28 x 3 1/2" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional durability and corrosion resistance with Black-Oxide Alloy Steel construction, ideal for harsh industrial environments.
• Superior load-bearing capacity thanks to a high tensile strength of 130,000 psi and Rockwell C39 hardness, reducing the risk of fastener failure.
• Precise and secure fastening ensured by the Class 3A thread fit and UNF fine thread, minimizing loosening under vibration.
• Efficient installation and flush finish with a standard 82° countersink angle and hex drive, allowing for easy, low-profile assembly.
• Reliable performance in critical applications due to compliance with ASME B18.3 and ASTM F835 standards, ensuring consistent quality.
• Environmental and safety compliance with RoHS 3 and REACH regulations, making them suitable for global industrial use.
• Optimized for partial threading needs, providing strong grip where full threading isn't required, enhancing versatility in assembly.

Professional Applications & Engineering Value

These 1/4"-28 UNF flat head socket cap screws are engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in demanding environments. Made from Black-Oxide Alloy Steel, they offer enhanced resistance to wear and environmental factors, extending service life in machinery, automotive, and heavy equipment applications. The fine thread and Class 3A fit provide tight tolerances, reducing the need for frequent retightening and improving overall assembly integrity. With a partially threaded design and 82° countersink, they enable secure, flush mounting in materials where precise load distribution is critical, making them a reliable choice for engineers seeking high-strength, compliant fasteners that meet rigorous ASME B18.3 and ASTM F835 standards.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including a Class 3A thread fit for high accuracy in UNF fine threading, with a thread size of 1/4"-28 and a minimum thread length of 1 1/4". Manufactured in compliance with ASME B18.3 and ASTM F835 specifications, it ensures consistent performance. Additionally, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming its suitability for safe, industrial use worldwide.