S-91257A818 5/8"-11 x 6" 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 applications
- Superior corrosion resistance through zinc yellow-chromate plating that extends service life in harsh environments
- Optimized torque transmission with external hex drive design for secure installation and removal
- Enhanced thread engagement with UNC coarse threads that resist loosening under vibration and dynamic loads
- Precise mechanical properties with Rockwell C33 hardness ensuring consistent performance and durability
- Reduced installation time with partially threaded shank design that simplifies alignment in structural applications
- Industry-standard compatibility with Class 2A thread fit ensuring proper mating with standard nuts and components
Professional Applications & Engineering Value
These Grade 8 hex head screws deliver critical engineering solutions for heavy-duty industrial applications where failure is not an option. The steel construction combined with zinc yellow-chromate plating provides exceptional corrosion protection for machinery, construction equipment, and structural assemblies exposed to demanding environments. The 5/8"-11 UNC coarse threads offer superior resistance to vibration-induced loosening, while the external hex drive ensures maximum torque application during installation. With partial threading along the 6" length, these fasteners provide optimal clamping force distribution in critical joints, making them ideal for construction machinery, industrial equipment, and heavy structural frameworks where 150,000 PSI tensile strength and reliable performance are paramount.
Specification Summary & Compliance
Manufactured to exacting standards with Class 2A thread fit precision and UNC thread form specifications. These hex head screws comply with ASME B18.2.1 and SAE J429 manufacturing standards, ensuring dimensional accuracy and mechanical properties. The fasteners are fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming they contain no restricted substances and meet international safety requirements for industrial applications.
