S-90429A257 1 1/4"-7 x 3 1/2" 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 demanding applications.
• Superior thread engagement and vibration resistance due to Class 3A fit and coarse UNC threads, ensuring a secure, long-lasting hold.
• High durability and wear resistance from Alloy Steel construction and Rockwell C37 hardness, extending service life.
• Efficient installation and removal with a 7/8" hex drive, providing high torque capability without slippage.
• Flush, clean finish achieved with an 82° countersink angle and flat head design, ideal for streamlined surfaces.
• Full-length threading for maximum grip along the entire 3 1/2" length, enhancing fastening security in thick materials.
• Compliance with rigorous industry standards including ASTM F835, RoHS 3, and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This alloy steel flat head screw is engineered to address critical challenges in heavy-duty industrial applications, such as machinery assembly, structural frameworks, and automotive components. Its 1 1/4"-7 UNC coarse thread and Class 3A fit provide superior resistance to loosening under vibration and dynamic loads, a common issue in high-stress environments. The fully threaded design ensures consistent clamping force across the entire 3 1/2" length, making it ideal for thick materials where uniform pressure is essential. Combined with the 82° countersink angle and hex drive, it allows for quick, secure installations that maintain a low-profile finish, reducing the risk of snagging and improving operational safety. These features make it a reliable choice for engineers and procurement specialists seeking durable, high-performance industrial fasteners that meet stringent quality and compliance requirements.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including UNC coarse threads with a Class 3A thread fit for tight tolerances and reliable assembly. It is manufactured in compliance with ASTM F835 specifications, ensuring consistent quality and performance. Additionally, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its environmental safety and suitability for global industrial use.