S-90429A266 1 1/4"-12 x 4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Class 3A thread fit with UNF fine threading provides superior engagement and vibration resistance, maintaining secure connections in precision assemblies.
• Alloy steel construction with Rockwell C37 hardness offers excellent wear resistance and durability, extending service life in harsh industrial environments.
• Partially threaded design with 3 1/8" minimum thread length allows for controlled clamping force and easier alignment in deep or variable material thicknesses.
• 82° countersink angle and standard flat head profile enable flush mounting for a smooth surface finish and improved aerodynamics in assembled structures.
• 7/8" hex drive compatibility facilitates efficient installation and removal with standard tools, reducing assembly time and labor costs.
• Compliance with ASTM F835, RoHS 3, and REACH regulations guarantees material quality and environmental safety, supporting sustainable and regulated industrial operations.

Professional Applications & Engineering Value

This 1 1/4"-12 UNF alloy steel flat head screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery fabrication, structural steelwork, and automotive assemblies. The fine thread spacing and Class 3A thread fit enhance grip and resistance to loosening under dynamic loads, while the alloy steel material with Rockwell C37 hardness withstands corrosion and mechanical stress. The partially threaded configuration allows precise tension control, minimizing material distortion. Ideal for applications requiring high-strength fastening and flush surface installation, this screw ensures long-term reliability and compliance with ASTM F835 specifications, making it a trusted choice for engineers prioritizing safety and performance.

Specification Summary & Compliance

This screw features precise inch system measurements with a Class 3A thread fit and UNF thread type for accurate engagement. It adheres to ASTM F835 manufacturing standards, ensuring consistent quality and performance. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of hazardous substances. The partial threading and 82° countersink angle meet industrial design requirements, supporting reliable use in regulated applications.