S-91257A949 7/8"-14 x 8" 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 for reliable performance in high-stress industrial applications.
- Superior corrosion resistance due to zinc yellow-chromate plating, extending service life in harsh environments.
- High hardness rating of Rockwell C33 ensures excellent wear resistance and durability under repeated use.
- Precise thread engagement with Class 2A fit and UNF fine threads for secure, vibration-resistant connections.
- Optimized for heavy-duty assembly featuring a 1 5/16" hex head and external drive for easy installation with standard tools.
- Partial threading design provides unthreaded shank strength where needed, ideal for clamping applications.
- Full regulatory compliance including ASME B18.2.1, RoHS 3, and REACH for guaranteed quality and environmental safety.
Professional Applications & Engineering Value
Engineered for demanding industrial applications, this Grade 8 hex head screw delivers critical reliability where failure is not an option. The steel construction combined with zinc yellow-chromate plating effectively combats corrosion in outdoor or chemically aggressive settings, reducing maintenance costs. Its 7/8"-14 UNF fine thread and Class 2A thread fit ensure tight, precise fastening that resists loosening under vibration, making it ideal for heavy machinery, structural assemblies, and automotive systems. The partial threading maximizes clamp load efficiency, while the external hex drive allows for high-torque installation with common tools, streamlining assembly processes in B2B procurement scenarios.
Specification Summary & Compliance
This fastener adheres to ASME B18.2.1 and SAE J429 Grade 8 specifications, ensuring dimensional accuracy and performance consistency. Threads are manufactured to Class 2A tolerance for reliable fit, with UNF fine thread profile (7/8"-14). The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of restricted hazardous substances and safe for industrial use.
