S-90409A211 3/4"-16 x 2 1/2" 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 high-stress industrial applications
• Superior wear resistance due to Rockwell C32 hardness, extending service life in demanding environments
• Enhanced stability and distribution from the integrated flange design, reducing the need for separate washers
• Precise thread engagement with Class 2A fit and fine UNF threading for secure, vibration-resistant connections
• Optimal torque transmission through the external hex drive and 1 1/8" head width for easy installation
• Reliable performance compliance meeting IFI 111/SAE J429 standards for quality-assured industrial use
• Versatile partial threading allowing unthreaded shank sections for improved shear strength in structural applications

Professional Applications & Engineering Value

This Grade 8 steel hex head screw delivers critical engineering solutions for heavy machinery, structural steel connections, and industrial equipment assemblies. The 3/4"-16 UNF fine thread configuration provides superior resistance to vibrational loosening while maintaining precise clamping force in high-cycle applications. The flanged design eliminates washer requirements and distributes load over a wider surface area (1 19/32" flange diameter), preventing surface damage and maintaining joint integrity. With partial threading and 150,000 psi tensile strength, this fastener excels in applications where both shear strength and tensile performance are paramount, making it ideal for construction equipment, automotive frames, and manufacturing machinery subjected to dynamic loads and harsh operating conditions.

Specification Summary & Compliance

Manufactured to exacting Class 2A thread fit tolerances with 3/4"-16 UNF fine thread spacing and right-hand threading. Complies with IFI 111 specification and SAE J429 standard for Grade 8 fasteners, ensuring consistent quality and performance. Features include 2 1/2" overall length, 1 3/4" minimum thread length, and external hex drive with 1 1/8" head width. Constructed from high-strength steel with Rockwell C32 hardness, delivering reliable performance in demanding industrial environments while meeting standard industry requirements for heavy-duty mechanical applications.