S-90429A148 1"-8 x 2 1/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 130,000 psi tensile strength for reliable performance in high-stress applications
• Superior corrosion resistance provided by the black-oxide finish on alloy steel, extending service life in demanding environments
• Precise thread engagement with Class 3A thread fit ensuring secure fastening and vibration resistance
• Optimized drive efficiency through the 5/8" hex drive design, allowing for high torque application without stripping
• Maximum holding power from the fully threaded UNC coarse thread design, preventing loosening under dynamic loads
• Consistent flush mounting with standard 82° countersink angle for seamless surface integration
• Enhanced durability with Rockwell C37 hardness maintaining structural integrity through repeated use

Professional Applications & Engineering Value

This black-oxide alloy steel flat head hex screw delivers critical engineering solutions for industrial assembly challenges. The combination of Class 3A thread fit and UNC coarse threading provides exceptional resistance to vibrational loosening in heavy machinery, construction equipment, and structural frameworks. The fully threaded design ensures maximum grip length throughout the fastener, distributing stress evenly across the entire engagement area. With its high-strength alloy steel construction and specialized black-oxide surface treatment, this screw withstands harsh environmental conditions while maintaining consistent clamping force. The 82° countersink angle facilitates perfect flush installation in predrilled holes, making it ideal for applications where surface smoothness and aerodynamic profiles are essential.

Specification Summary & Compliance

Manufactured to exacting Class 3A thread tolerances with UNC coarse thread form (1"-8) and right-hand thread direction. Complies with ASME B18.3 and ASTM F835 specifications for dimensional accuracy and mechanical properties. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance standards for environmental safety. Features include 2-1/4" length, 1.938" head diameter, and standard flat head profile engineered for industrial fastener applications.