S-91247A329 7/16"-20 x 3 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior load-bearing capacity with 120,000 psi tensile strength for reliable performance in demanding applications
• Enhanced corrosion resistance through zinc plating, extending service life in various industrial environments
• Precise thread engagement with Class 2A fit and UNF fine threading for secure fastening and vibration resistance
• Optimized torque transmission through external hex drive design and 5/8" head width for easy installation
• Consistent mechanical properties with Rockwell C25 hardness, ensuring dimensional stability under stress
• Versatile partial threading allowing for both clamping and alignment functions in assembly operations
• Regulatory compliance assurance meeting multiple industry standards for quality and environmental safety

Professional Applications & Engineering Value

This Grade 5 steel hex head screw delivers exceptional engineering value through its balanced combination of high tensile strength and controlled hardness. The 7/16"-20 UNF fine threading provides superior resistance to vibrational loosening in machinery, automotive, and structural applications where dynamic loads are present. The zinc plated finish creates a protective barrier against oxidation and environmental degradation, significantly extending maintenance intervals in industrial settings. With partial threading design, this fastener offers precise clamping force distribution while maintaining unthreaded shank strength. The external hex drive configuration ensures compatibility with standard tools and facilitates high-torque installation in confined spaces, making it ideal for heavy equipment assembly, construction frameworks, and manufacturing fixtures requiring reliable, long-term fastening solutions.

Specification Summary & Compliance

Manufactured to precise inch system dimensions with Class 2A thread fit tolerance ensuring consistent mating with UNF threaded components. Complies with ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and mechanical properties. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards, confirming restriction of hazardous substances. The Grade 5 classification guarantees minimum tensile strength of 120,000 psi and Rockwell C25 hardness for consistent performance across production batches.