S-91257A492 1/2"-20 x 7 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws
High-Strength Grade 8 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 150,000 psi tensile strength, ideal for high-stress industrial assemblies.
- Superior corrosion resistance due to zinc yellow-chromate plating, extending service life in harsh environments.
- Reliable fine thread engagement with UNF 1/2"-20 threading and Class 2A fit, ensuring precise, vibration-resistant connections.
- High hardness rating of Rockwell C33, providing excellent wear resistance and durability under repeated use.
- Optimized for heavy-duty applications with a Grade 8 strength rating and external hex drive for secure, high-torque installation.
- Partial threading design allows for unthreaded shank strength where maximum clamping force is required.
- Compliance with major industry standards including ASME B18.2.1 and SAE J429, guaranteeing consistent quality and performance.
Professional Applications & Engineering Value
This Grade 8 hex head screw is engineered to address critical fastening challenges in demanding sectors such as heavy machinery, construction, and automotive assemblies. The UNF fine thread and Class 2A thread fit provide superior resistance to loosening under vibration, a common failure point in dynamic environments. Made from high-strength steel and finished with zinc yellow-chromate plating, it combats corrosion effectively, reducing maintenance needs and downtime. The external hex drive and robust head design facilitate easy installation with standard tools, even in high-torque scenarios, making it a reliable choice for structural and mechanical applications where safety and longevity are paramount.
Specification Summary & Compliance
This fastener meets ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and mechanical properties. Threads conform to UNF 1/2"-20 with a Class 2A fit for consistent engagement. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of hazardous substances and safe for industrial use across regulated markets.
