S-91253A840 3/4"-16 x 3 1/2" 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 high-stress industrial applications, reducing the risk of fastener failure.
• Class 3A thread fit provides superior precision and tighter tolerances for secure, vibration-resistant assemblies in critical machinery.
• Black-oxide coating on alloy steel enhances corrosion resistance and durability, extending service life in harsh operating environments.
• 82° countersink angle and flat head design allows for flush mounting, improving aesthetics and preventing snagging in assembled components.
• Partially threaded shank offers optimal grip and clamping force control, ideal for materials requiring precise fastening pressure.
• Hex drive (1/2") enables easy installation with standard tools, reducing assembly time and labor costs in production lines.
• Compliance with ASTM F835, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations, supporting global supply chain requirements.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these 3/4"-16 UNF flat head screws address common challenges like vibration loosening and material fatigue. The black-oxide alloy steel construction, combined with a Rockwell C37 hardness rating, provides exceptional wear resistance and load-bearing capacity, making them suitable for heavy-duty machinery, automotive assemblies, and structural frameworks. The fine thread spacing and Class 3A thread fit ensure secure fastening in precision components, minimizing maintenance needs. Ideal for applications requiring flush mounting with an 82° countersink, these screws enhance safety and efficiency in manufacturing, construction, and equipment maintenance, delivering long-term reliability under high-stress conditions.

Specification Summary & Compliance

This product features a 3/4"-16 UNF thread with Class 3A fit for high precision, a minimum thread length of 2 inches, and partial threading for controlled clamping. It complies with ASTM F835 specifications for mechanical properties, and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, ensuring safety and regulatory adherence in global markets.