S-91253A307 1/4"-28 x 3/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior tensile strength of 130,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure.
• Precision Class 3A thread fit provides excellent engagement and vibration resistance, minimizing loosening in dynamic applications.
• Black-oxide finish on alloy steel offers enhanced corrosion resistance and a durable, non-reflective surface for harsh environments.
• Fully threaded design allows for maximum grip and uniform load distribution along the entire length.
• 82° countersink angle and flat head enable a flush, low-profile installation, ideal for applications requiring a smooth surface finish.
• 5/32" hex drive facilitates easy installation and removal with standard tools, improving assembly efficiency.
• Compliance with ASME B18.3 and ASTM F835 guarantees consistent quality and interchangeability in industrial assemblies.

Professional Applications & Engineering Value

This 1/4"-28 UNF flat head socket cap screw is engineered to address critical challenges in industrial and mechanical systems where precision and durability are paramount. The black-oxide alloy steel construction, combined with a Rockwell C39 hardness, provides exceptional resistance to wear and environmental factors, making it suitable for automotive, aerospace, and heavy machinery applications. The fine thread spacing and Class 3A thread fit ensure tight, secure fastening in components subject to vibration, reducing maintenance needs. Its fully threaded body and 82° countersink angle allow for seamless integration into countersunk holes, offering a sleek finish while maintaining structural integrity under loads up to 130,000 psi tensile strength.

Specification Summary & Compliance

This screw adheres to Class 3A thread fit tolerances for precision, with UNF fine threads and a right-hand thread direction. It meets ASME B18.3 and ASTM F835 specifications for dimensional accuracy and performance. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring environmental safety and regulatory adherence in global supply chains.