S-91257A917 7/8"-9 x 4" 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 tensile strength of 150,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
- Superior corrosion resistance from zinc yellow-chromate plating extends service life in harsh industrial environments, minimizing maintenance needs.
- High hardness rating (Rockwell C33) provides excellent wear resistance, maintaining structural integrity under repeated loads.
- Coarse UNC threading with Class 2A fit allows for quick installation and secure fastening, improving assembly efficiency.
- Partially threaded design offers optimal grip and clamping force, ideal for applications requiring precise joint control.
- External hex drive enables easy torque application with standard tools, reducing installation time and effort.
- Compliance with industry standards (ASME B18.2.1, SAE J429) ensures consistent quality and interoperability in demanding setups.
Professional Applications & Engineering Value
This Grade 8 hex head screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, structural frameworks, and automotive systems. The steel material combined with zinc yellow-chromate plating provides robust protection against corrosion and oxidation, extending component lifespan in exposed or humid conditions. With a coarse UNC thread and partial threading, it ensures rapid installation and reliable clamping, reducing vibration-induced loosening. Its 150,000 psi tensile strength and Rockwell C33 hardness make it suitable for high-load applications, offering engineers a dependable solution for maintaining structural integrity and safety in demanding environments like construction, mining, and manufacturing.
Specification Summary & Compliance
This fastener adheres to precise dimensional tolerances, including Class 2A thread fit and UNC coarse threading (7/8"-9), ensuring consistent performance. It meets ASME B18.2.1 and SAE J429 specifications for manufacturing quality. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmental safety and regulatory requirements in global industrial supply chains.
