S-90409A190 5/8"-18 x 2 3/4" IFI 111, SAE J429 High-Strength Grade 8 Steel Flanged Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 150,000 psi tensile strength for reliable performance in high-stress applications
• Superior corrosion resistance and durability thanks to Grade 8 steel construction and Rockwell C32 hardness
• Secure, vibration-resistant fastening achieved through UNF fine threading and Class 2A thread fit precision
• Easy installation and removal with standard external hex drive and 15/16" head width for common tool compatibility
• Enhanced stability and load distribution from the integrated flange design, eliminating the need for separate washers
• Industry-standard compliance assurance meeting IFI 111/SAE J429 specifications for consistent quality and interchangeability
• Environmental regulation adherence with full RoHS 3 and REACH compliance for safe, sustainable usage

Professional Applications & Engineering Value

This Grade 8 steel hex head screw delivers critical reliability in demanding industrial environments where failure is not an option. The 5/8"-18 UNF fine thread provides superior resistance to loosening under vibration, making it ideal for heavy machinery, automotive assemblies, and structural steel connections. The partially threaded design ensures precise clamp load concentration while the flanged head distributes pressure evenly, reducing surface damage and simplifying installation. With 150,000 psi tensile strength and Rockwell C32 hardness, it withstands extreme mechanical stresses while maintaining integrity in corrosive environments. Engineered to SAE J429 standards, this fastener offers predictable performance across maintenance schedules and replacement cycles.

Specification Summary & Compliance

This hex head screw features precise Class 2A thread fit tolerances with 5/8"-18 UNF fine threading and right-hand thread direction. Manufacturing complies with IFI 111 SAE J429 specifications, ensuring dimensional accuracy and mechanical properties. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, containing no restricted substances above threshold limits. Critical dimensions include 2 3/4" length, 1 21/64" flange diameter, and 1 1/2" minimum thread length for consistent performance across applications.