S-91247A453 5/8"-18 x 7" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capability with 120,000 psi tensile strength for reliable performance in demanding applications
• Superior corrosion resistance through zinc plating, extending service life in harsh industrial environments
• Precise thread engagement with Class 2A fit and UNF fine threading for vibration resistance and secure fastening
• Optimized drive efficiency featuring external hex design and 15/16" head width for high-torque installation
• Enhanced durability from Grade 5 steel construction with Rockwell C25 hardness for repeated use
• Versatile partial threading allowing both clamping and alignment functions in assembly operations
• Full regulatory compliance meeting ASME B18.2.1, SAE J429 standards plus RoHS 3 and REACH environmental directives

Professional Applications & Engineering Value

This Grade 5 steel hex head screw delivers critical engineering solutions for industrial assembly challenges. The 5/8"-18 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 sacrificial barrier against oxidation, significantly extending service life in environments exposed to moisture or chemicals. With partial threading along its 7" length, this fastener enables precise clamping force distribution while allowing unthreaded sections to function as alignment pins or pivot points. The external hex drive configuration ensures reliable torque transmission during installation, making it ideal for high-stress connections requiring consistent preload values across multiple fasteners.

Specification Summary & Compliance

Manufactured to ASME B18.2.1 and SAE J429 specifications, this hex head screw maintains Class 2A thread fit tolerances for consistent engagement. The 5/8"-18 UNF fine thread configuration ensures precise pitch control with minimum thread length of 1-3/4". Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations guarantees safe use across international markets. Mechanical properties include Rockwell C25 hardness and 120,000 psi tensile strength as defined by Grade 5 classification standards.