S-91253A288 1/4"-20 x 7/16" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional durability with Black-Oxide Alloy Steel construction providing superior corrosion resistance and long-term reliability in harsh industrial environments.
• High tensile strength of 130,000 psi ensures secure, vibration-resistant fastening for critical applications requiring maximum load-bearing capacity.
• Precision Class 3A thread fit delivers smooth installation and consistent clamping force, reducing assembly time and improving joint integrity.
• 82° countersink angle flat head design allows for flush mounting in tapered holes, creating clean, professional finishes without protrusion.
• Hex drive (5/32") compatibility enables high-torque application with standard tools, minimizing slippage and tool wear during installation.
• Full threading along the 7/16" length provides maximum grip and adjustment flexibility across the entire fastener engagement area.
• Compliance with ASTM F835, RoHS 3, and REACH standards guarantees material quality, environmental safety, and global regulatory acceptance for industrial use.

Professional Applications & Engineering Value

These 1/4-20 UNC flat head screws deliver critical engineering solutions where high-strength fastening and flush surface mounting are paramount. The Black-Oxide Alloy Steel material, combined with Rockwell C39 hardness, resists wear and environmental degradation in demanding applications like machinery assembly, automotive components, and structural frameworks. The coarse UNC thread and Class 3A fit ensure rapid installation with reduced cross-threading risks, while the 82° countersink angle seamlessly integrates into tapered holes for aerodynamically smooth or safety-critical surfaces. Ideal for replacing metric alternatives in North American industrial settings, these screws provide reliable performance under dynamic loads and vibrations, supported by full compliance with international specifications.

Specification Summary & Compliance

This flat head screw features a 1/4"-20 UNC coarse thread with Class 3A precision tolerance for optimal fit and strength. Manufacturing adheres to ASTM F835 specifications, ensuring consistent dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted hazardous substances and supporting sustainable procurement practices in industrial supply chains.