S-91253A807 5/8"-11 x 3 1/4" 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 in heavy-duty applications, reducing the risk of fastener failure under high stress.
• Class 3A thread fit provides superior precision and tighter tolerances, offering improved assembly consistency and vibration resistance in machinery.
• Black-oxide coating on alloy steel enhances corrosion resistance and durability, extending service life in harsh industrial environments.
• 3/8" hex drive design allows for secure tool engagement and efficient installation, minimizing slippage and speeding up assembly processes.
• Partially threaded shank with coarse UNC threads delivers strong holding power and easier alignment, ideal for materials requiring high clamp force.
• Compliance with ASTM F835, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations, supporting safe and sustainable operations.
• 82° countersink angle and flat head profile enable flush mounting, reducing protrusion risks and improving aesthetics in finished assemblies.

Professional Applications & Engineering Value

This 5/8"-11 UNC flat head screw is engineered to address critical challenges in industrial fastening, such as vibration loosening and material fatigue. Constructed from black-oxide alloy steel with a Rockwell C37 hardness, it withstands high-load conditions in machinery, construction, and automotive sectors. The coarse thread and Class 3A fit enhance grip in soft or composite materials, while the partially threaded design concentrates stress for improved joint integrity. Ideal for heavy-duty applications like structural frameworks and equipment assembly, it ensures long-term reliability and reduces maintenance needs, backed by compliance with ASTM F835 and environmental standards.

Specification Summary & Compliance

This screw features a 5/8"-11 UNC coarse thread with Class 3A thread fit for precise dimensional accuracy, a 3 1/4" length, and partially threaded configuration. It meets ASTM F835 specifications for mechanical properties and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and industry-standard reliability.