S-91247A448 5/8"-18 x 5" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with Grade 5 steel construction providing 120,000 psi tensile strength for demanding industrial applications
• Superior corrosion resistance through zinc plating that protects against environmental degradation in harsh operating conditions
• Precise thread engagement with Class 2A UNF fine threading ensuring reliable fastening and vibration resistance
• Optimized torque transmission via external hex drive design that prevents tool slippage during installation
• Enhanced durability with Rockwell C25 hardness maintaining structural integrity under repeated stress
• Versatile partial threading allowing both secure clamping and adjustable positioning in assembly applications
• Right-hand thread orientation providing standard installation compatibility across industrial equipment

Professional Applications & Engineering Value

This 5/8"-18 UNF Grade 5 hex head screw delivers critical performance in heavy machinery, structural frameworks, and industrial equipment where high tensile strength and vibration resistance are paramount. The zinc plated finish provides essential corrosion protection for outdoor applications or environments with moisture exposure. The UNF fine threading offers superior resistance to loosening under dynamic loads compared to coarse threads, while the external hex drive enables high-torque installation without cam-out issues. The partially threaded design allows for both secure clamping on the unthreaded shank and adjustable fastening where needed, making it ideal for construction, automotive, and manufacturing applications requiring reliable, high-strength fastening solutions.

Specification Summary & Compliance

Manufactured to ASME B18.2.1 and SAE J429 Grade 5 specifications with Class 2A thread fit ensuring precision dimensional accuracy. Features 5/8"-18 UNF fine thread configuration with right-hand orientation and 5" total length. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting international standards for industrial fastener applications.