S-91253A986 1 1/4"-7 x 4" 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 longevity in harsh industrial environments.
• Maximum torque transfer enabled by the 7/8" hex drive design, reducing tool slippage and ensuring secure installation in high-stress applications.
• High load-bearing capacity with 130,000 psi tensile strength and Rockwell C37 hardness, offering reliable performance under extreme mechanical stress.
• Precise thread engagement through Class 3A fit and UNC coarse threading, ensuring vibration resistance and easy alignment in heavy machinery.
• Flush mounting capability with an 82° countersink angle and standard flat head profile, ideal for streamlined surfaces and reduced protrusion risks.
• Full-threaded design for consistent grip along the entire 4" length, enhancing stability in thick materials or structural assemblies.
• Regulatory compliance with ASTM F835, RoHS 3, and REACH standards, guaranteeing safety and environmental responsibility for global industrial use.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, this 1 1/4"-7 UNC flat head hex screw addresses critical challenges in heavy machinery, construction, and automotive assemblies. The black-oxide alloy steel material combats rust and wear, while the Class 3A thread fit and coarse UNC threading prevent loosening under vibration, a common pain point in dynamic environments. With a fully threaded 4" length and 82° countersink, it ensures deep penetration and seamless flush mounting in metal frameworks or equipment housings. The 7/8" hex drive facilitates high-torque applications, reducing installation time and enhancing reliability in sectors like manufacturing and infrastructure, where fastener failure can lead to costly downtime.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including UNC coarse threads with a Class 3A fit for tight tolerances and optimal thread engagement. It meets ASTM F835 specifications for mechanical properties, ensuring consistent performance in industrial fastening. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it supports environmental and safety requirements, making it suitable for global supply chains. The combination of 130,000 psi tensile strength and Rockwell C37 hardness underscores its reliability in high-stress applications.