S-91253A842 3/4"-16 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 provides superior precision and tighter tolerances for secure, vibration-resistant connections in critical assemblies.
• Black-oxide coating on alloy steel offers enhanced corrosion resistance and a durable, non-reflective finish suitable for harsh industrial environments.
• 1/2" hex drive design allows for high-torque installation with standard tools, speeding up assembly and reducing labor time.
• 82° countersink angle and flat head profile enable a flush, low-profile fit that minimizes protrusion and improves aerodynamics or safety in machinery.
• Partially threaded shank provides unthreaded grip length for better clamping force distribution, ideal for materials requiring precise joint integrity.
• Compliance with ASTM F835, RoHS 3, and REACH ensures adherence to rigorous industry standards and environmental regulations, supporting global supply chain requirements.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, this 3/4"-16 UNF flat head screw addresses common challenges like vibration loosening and material fatigue. The black-oxide alloy steel construction, combined with a Rockwell C37 hardness, delivers outstanding durability and wear resistance in machinery, construction, and automotive assemblies. Its fine UNF thread and Class 3A fit ensure precise engagement in tapped holes, maintaining integrity under dynamic loads. The 82° countersink and flat head design allow for seamless integration into surfaces, reducing snag hazards and improving aesthetic finishes. Ideal for use in high-stress environments where reliability and compliance with ASTM F835 are critical, this screw provides long-term value by minimizing maintenance and replacement costs.

Specification Summary & Compliance

This screw features a 3/4"-16 UNF fine thread with Class 3A thread fit for high precision, a minimum thread length of 2", and a total length of 4". It meets ASTM F835 specifications for mechanical properties and is manufactured in accordance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free of restricted substances and suitable for international industrial markets.