S-91263A375 4-40 x 3/16" 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.
• Class 3A thread fit provides superior precision and tighter tolerances for secure, vibration-resistant assemblies in demanding applications.
• Zinc-plated alloy steel construction offers excellent corrosion resistance, extending service life in harsh industrial environments.
• Fully threaded design with coarse UNC spacing allows for faster installation and consistent holding power across the entire length.
• 82° countersink angle and flat head profile enable a flush, low-profile finish, ideal for applications where surface clearance is critical.
• Hex drive (1/16") ensures easy, slip-resistant installation with standard tools, improving assembly efficiency.
• Compliance with ASTM F835, RoHS 3, and REACH guarantees that these screws meet rigorous industry standards for safety and environmental responsibility.

Professional Applications & Engineering Value

Engineered for precision and durability, these 4-40 UNC flat head screws are ideal for industrial and mechanical assemblies where space constraints and reliability are paramount. The zinc-plated alloy steel material resists corrosion, making them suitable for use in electronics, machinery, and automotive components exposed to moisture or chemicals. The Class 3A thread fit and coarse threading ensure secure fastening with minimal backlash, addressing common issues like loosening under vibration. With a fully threaded design and standard 82° countersink, these screws provide consistent clamping force and a smooth, flush finish, enhancing both performance and aesthetics in high-strength applications.

Specification Summary & Compliance

This product features precise Class 3A thread fit per UNC standards, ensuring tight tolerances for reliable performance. Manufactured from zinc-plated alloy steel, it meets ASTM F835 specifications for mechanical properties, including a tensile strength of 130,000 PSI and Rockwell C39 hardness. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) confirms adherence to environmental and safety regulations, supporting sustainable procurement practices.