S-91268A237 5/16"-18 x 4 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 heavy-duty applications requiring maximum reliability
- Superior wear resistance due to Rockwell C33 hardness, ensuring extended service life in demanding environments
- Secure fastening performance with Class 2A thread fit providing consistent engagement and vibration resistance
- Quick installation efficiency through UNC coarse threading and external hex drive design
- Optimized material distribution with partial threading design for balanced strength-to-weight ratio
- Industry-standard compatibility meeting ASME B18.2.1 and SAE J429 specifications for reliable interchangeability
- Environmental compliance assurance with RoHS 3 and REACH regulations for global industrial use
Professional Applications & Engineering Value
This Grade 8 hex head screw delivers critical engineering solutions for industrial machinery, structural assemblies, and heavy equipment applications. The 5/16"-18 UNC coarse threading combined with partial threading design prevents thread stripping in soft materials while maintaining superior clamp load distribution. The external hex drive facilitates high-torque installation with standard tools, reducing assembly time in production environments. Manufactured from high-strength steel with Rockwell C33 hardness, this fastener withstands extreme vibration, shock loads, and environmental stressors common in construction, automotive, and manufacturing sectors. The 4-1/2" length provides sufficient engagement for thick material sections while the right-hand thread direction ensures compatibility with standard installation procedures.
Specification Summary & Compliance
This hex head screw maintains precise Class 2A thread fit per UNC standards with 5/16"-18 thread size and 7/8" minimum thread length. Manufacturing complies with ASME B18.2.1 and SAE J429 Grade 8 specifications, ensuring dimensional accuracy and mechanical properties. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, making it suitable for regulated industries and international projects requiring certified components.
