S-91257A413 1/4"-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 for reliable performance in high-stress applications
- Superior corrosion resistance through zinc yellow-chromate plating, extending service life in harsh environments
- Optimized torque transmission with external hex drive design for secure installation and removal
- Enhanced thread engagement with UNC coarse threading that resists vibration loosening and simplifies alignment
- Precision manufacturing to Class 2A thread fit ensuring consistent performance and compatibility
- Rockwell C33 hardness providing excellent wear resistance and durability under repeated use
- Industry compliance with ASME B18.2.1 and SAE J429 specifications for quality assurance
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 combination of high-strength steel material and Rockwell C33 hardness ensures exceptional resistance to shear and tensile forces, making them ideal for structural connections in construction, machinery assembly, and equipment manufacturing. The zinc yellow-chromate plating provides superior corrosion protection in challenging environments, while the 1/4"-20 UNC coarse threading offers excellent vibration resistance and faster installation in thick materials. With partial threading and 7 1/2" length, these fasteners provide optimal clamping force distribution for demanding applications requiring reliable, long-lasting connections.
Specification Summary & Compliance
This Grade 8 hex head screw features precise Class 2A thread fit with 1/4"-20 UNC coarse threading and 7 1/2" overall length. Manufactured to meet ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and performance reliability. The fastener maintains 150,000 PSI tensile strength and Rockwell C33 hardness with zinc yellow-chromate plating for corrosion protection. The product complies with industry standards for heavy-duty fastening applications requiring certified performance metrics.
