S-91247A012 1/4"-28 x 1 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior tensile strength with 120,000 psi rating ensures reliable performance in high-stress industrial applications
• Enhanced corrosion resistance through zinc plating protects against environmental degradation in demanding conditions
• Precise thread engagement with Class 2A fit and UNF fine threads provides superior vibration resistance and secure fastening
• Optimal torque transmission through external hex drive design allows for efficient installation with standard tools
• Grade 5 strength classification delivers consistent mechanical properties for critical assembly requirements
• Partially threaded design enables precise clamping force distribution and prevents joint loosening
• Regulatory compliance assurance with RoHS 3 and REACH standards meets international environmental and safety requirements

Professional Applications & Engineering Value

This Grade 5 hex head screw delivers exceptional engineering value through its zinc plated steel construction and UNF fine threading, specifically designed to address common industrial fastening challenges. The combination of 120,000 psi tensile strength and Rockwell C25 hardness ensures reliable performance in heavy machinery, automotive assemblies, and structural applications where vibration resistance is critical. The 1/4"-28 thread size with fine pitch provides superior clamping force distribution, preventing joint failure in dynamic loading conditions. The external hex drive facilitates quick installation with standard tools, while the partially threaded design allows for precise load bearing across the shank, making it ideal for applications requiring specific grip lengths and shear strength characteristics.

Specification Summary & Compliance

This fastener maintains Class 2A thread fit tolerance per UNF standards with precise 1/4"-28 fine threading and 1-1/2" length. Manufactured to ASME B18.2.1 specifications and SAE J429 Grade 5 requirements, ensuring dimensional accuracy and mechanical consistency. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, providing assurance for international industrial applications requiring strict material composition standards.