S-91253A918 1"-8 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 under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the Black-Oxide finish on Alloy Steel extends service life and maintains integrity in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening over time.
• Heavy-duty hex drive (5/8") allows for high-torque installation with common tools, speeding up assembly while preventing stripping.
• Fully threaded coarse (UNC) design offers maximum grip and load distribution along the entire length, enhancing joint stability.
• High hardness (Rockwell C37) resists wear and deformation, ensuring repeated use without compromising thread integrity.
• Compliance with ASTM F835, RoHS 3, and REACH guarantees material safety, environmental responsibility, and consistent quality for global supply chains.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these 1"-8 UNC flat head screws solve critical challenges in machinery, construction, and structural assemblies where vibration resistance and long-term durability are paramount. The Black-Oxide Alloy Steel construction combats rust and chemical exposure, ideal for outdoor or corrosive settings. The coarse thread spacing and Class 3A fit ensure quick, secure fastening in metals or tough materials, reducing installation time while preventing backlash. With a fully threaded shank and 82° countersink angle, they provide flush mounting and even stress distribution, minimizing point loads and extending the life of connected components.

Specification Summary & Compliance

This screw adheres to UNC coarse thread standards with a Class 3A thread fit for precision assembly. Dimensions include a 1"-8 thread size, 3 1/2" length, and hex drive 5/8". It meets ASTM F835 specifications for mechanical properties and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring no restricted substances and environmental safety in industrial use.