S-91247A418 9/16"-18 x 5 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws
Medium-Strength Grade 5 Steel Hex Head Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Exceptional load-bearing capacity with 120,000 psi tensile strength, ideal for high-stress industrial assemblies.
- Superior corrosion resistance due to zinc plating, extending service life in harsh environments.
- Reliable fine thread engagement with 9/16"-18 UNF threading and Class 2A fit, ensuring vibration resistance and secure fastening.
- Optimized for high-torque applications featuring an external hex drive and Grade 5 strength, allowing for easy installation with standard tools.
- Enhanced durability and wear resistance from Rockwell C25 hardness, reducing deformation under heavy loads.
- Versatile partial threading design providing strong grip where full threading isn't required, improving assembly efficiency.
- Compliance with major industry standards including ASME B18.2.1 and SAE J429, guaranteeing consistent quality and performance.
Professional Applications & Engineering Value
This Grade 5 hex head screw is engineered to address critical challenges in heavy-duty industrial and construction applications. The zinc plated steel construction offers reliable protection against rust and corrosion, which is essential for outdoor or moisture-exposed environments. Its 9/16"-18 UNF fine thread and Class 2A thread fit provide superior resistance to loosening under vibration, a common issue in machinery and structural frameworks. The partially threaded design allows for precise clamping force control, making it ideal for assemblies where unthreaded shank sections bear shear loads. With a tensile strength of 120,000 psi and external hex drive, it supports high-torque installation in demanding sectors such as equipment manufacturing, infrastructure, and automotive systems, ensuring long-term reliability and reduced maintenance.
Specification Summary & Compliance
This fastener adheres to Class 2A thread tolerance for consistent fit and UNF fine thread standards. It meets ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and mechanical properties. The product is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it is free from hazardous substances and safe for various industrial uses.
