S-91253A723 1/2"-13 x 2 3/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional strength and durability with 130,000 psi tensile strength and Rockwell C39 hardness for reliable performance in demanding applications.
• Superior corrosion resistance thanks to the black-oxide finish on alloy steel, extending service life in harsh industrial environments.
• Secure and flush fastening enabled by the standard flat head profile and 82° countersink angle, ideal for applications requiring a smooth surface.
• Easy installation and high torque transmission with the 5/16" hex drive, reducing assembly time and preventing stripping.
• Precise thread engagement with Class 3A UNC coarse threading, ensuring consistent fit and reducing the risk of cross-threading.
• Optimized load distribution through the partially threaded design, minimizing stress concentration in critical joints.
• Full regulatory compliance meeting ASTM F835, RoHS 3, and REACH standards for safe, environmentally conscious industrial use.

Professional Applications & Engineering Value

These flat head hex drive screws are engineered to address common industrial fastening challenges, such as vibration loosening and material fatigue. The black-oxide alloy steel construction provides excellent resistance to rust and wear, making them suitable for heavy machinery, automotive assemblies, and structural frameworks exposed to variable loads. The 1/2"-13 UNC coarse thread and Class 3A thread fit ensure quick, reliable installation with minimal risk of thread damage, while the partially threaded design enhances grip in softer materials. Combined with a 82° countersink angle, these screws deliver a flush, secure fit that maintains integrity under high-stress conditions, reducing maintenance needs and downtime in critical operations.

Specification Summary & Compliance

This screw features precise UNC coarse threading with a Class 3A thread fit for superior dimensional accuracy. It is manufactured in accordance with ASTM F835 specifications, ensuring consistent quality and performance. Additionally, the product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible procurement and use in global industrial markets.