S-91247A570 1/4"-20 x 8" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• High tensile strength of 120,000 PSI ensures reliable performance in demanding applications, reducing the risk of fastener failure under heavy loads.
• Zinc plating finish provides excellent corrosion resistance, extending the service life of the screw in various environmental conditions.
• Grade 5 steel construction with Rockwell C25 hardness offers superior durability and resistance to wear, ideal for repetitive industrial use.
• UNC coarse threading with Class 2A fit allows for quick and easy installation while maintaining secure fastening in coarse-grained materials.
• Partially threaded design enhances clamping force and prevents loosening in assemblies requiring precise tension control.
• External hex head enables straightforward tightening with standard tools, improving efficiency in maintenance and assembly tasks.
• Compliance with ASME B18.2.1, SAE J429, RoHS 3, and REACH ensures adherence to industry standards and environmental regulations for safe, reliable use.

Professional Applications & Engineering Value

This Grade 5 hex head screw is engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in harsh environments. Made from high-strength steel and featuring a zinc-plated finish, it resists rust and wear, making it ideal for heavy-duty applications in construction, machinery, and automotive assemblies. The UNC coarse thread and partial threading design provide superior grip and reduce the risk of strip-out in coarse materials, while the external hex drive allows for easy installation with common tools. By combining robust materials and precise thread specifications, this screw delivers long-lasting performance and reliability in demanding engineering projects.

Specification Summary & Compliance

This screw meets precise dimensional standards, including Class 2A thread fit for consistent engagement and UNC coarse threading with a size of 1/4"-20. It is manufactured in compliance with ASME B18.2.1 and SAE J429 specifications, ensuring high quality and interoperability. Additionally, it adheres to environmental regulations such as RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming its safety and sustainability for industrial use.