S-91247A032 1/4"-28 x 5" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 PSI ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Zinc plating provides a durable, corrosion-resistant barrier, extending the service life of the screw in various industrial environments.
• Grade 5 steel construction with Rockwell C25 hardness offers an optimal balance of strength and toughness, resisting wear and deformation.
• UNF fine thread design delivers superior vibration resistance and enhanced clamping force compared to coarse threads, maintaining joint integrity.
• Partially threaded shank allows for precise clamping on specific sections, minimizing thread damage and simplifying installation.
• External hex drive and hex head enable high-torque application with standard tools, ensuring secure fastening and easy maintenance.
• Class 2A thread fit guarantees consistent, reliable engagement with nuts and tapped holes, facilitating smooth assembly and disassembly.

Professional Applications & Engineering Value

This Grade 5 hex head screw is engineered to address critical challenges in heavy machinery, automotive assemblies, and structural frameworks where vibration resistance and high tensile loads are common. The zinc plated steel construction combats corrosion in harsh environments, while the 1/4"-28 UNF fine thread enhances grip and stability, preventing loosening under dynamic stresses. Its partially threaded design concentrates clamping force precisely, reducing the risk of cross-threading and improving load distribution. Ideal for industrial fastening in construction, manufacturing, and equipment repair, this screw ensures long-term reliability and compliance with rigorous engineering standards, minimizing downtime and maintenance costs.

Specification Summary & Compliance

This screw adheres to Class 2A thread fit tolerances and UNF fine thread standards, ensuring precise dimensional accuracy. It meets ASME B18.2.1 and SAE J429 specifications for consistent manufacturing quality. Additionally, it is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of hazardous substances and supporting environmental safety in industrial use.