S-91263A731 5/16"-18 x 1 1/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating that protects against rust in demanding industrial environments
• Exceptional tensile strength of 130,000 PSI ensures reliable performance under high-stress applications
• Precise Class 3A thread fit provides secure, vibration-resistant connections with minimal risk of loosening
• Full UNC coarse threading enables faster installation and superior holding power in various materials
• 82° countersink angle allows for flush mounting with standard countersunk holes
• Hex drive design offers superior torque transmission and prevents cam-out during installation
• Comprehensive compliance with ASTM F835, RoHS 3, and REACH ensures quality and environmental responsibility

Professional Applications & Engineering Value

These zinc-plated alloy steel flat head screws deliver exceptional engineering value for industrial applications requiring reliable fastening solutions. The combination of 130,000 PSI tensile strength and Rockwell C39 hardness ensures these UNC threaded screws maintain structural integrity under heavy loads and vibration. The Class 3A thread fit provides precision engagement that prevents stripping and ensures consistent performance in manufacturing equipment, machinery assembly, and structural applications. The zinc plating offers corrosion protection while the 82° countersink creates clean, flush finishes in metal fabrication and woodworking projects. These hex drive screws are engineered to solve common fastening challenges including vibration-induced loosening, corrosion degradation, and installation efficiency.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit precision and UNC coarse threading specifications. These flat head screws comply with ASTM F835 manufacturing standards and maintain dimensional accuracy throughout production. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) requirements for chemical safety. The 5/16"-18 thread size with 1 1/4" length provides standardized compatibility across industrial applications requiring reliable fastening solutions.