S-91286A225 3/8"-16 x 4 1/4" 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 load-bearing capacity with 150,000 psi tensile strength for critical structural applications
- Superior corrosion resistance provided by zinc-flake coating, extending service life in harsh environments
- Reliable fastening performance through Grade 8 classification and Rockwell C33 hardness
- Easy installation and removal with external hex drive design and coarse UNC threading
- Precise thread engagement ensured by Class 2A thread fit for consistent clamping force
- Optimized strength-to-weight ratio with partial threading design reducing unnecessary material
- Industry-standard compatibility meeting ASME B18.2.1 and SAE J429 specifications
Professional Applications & Engineering Value
This Grade 8 hex head screw delivers exceptional engineering value for heavy-duty industrial applications where failure is not an option. The zinc-flake coated steel construction provides superior corrosion protection for equipment exposed to moisture, chemicals, or outdoor elements. The 3/8"-16 UNC coarse threading ensures rapid installation and superior resistance to vibration loosening in machinery, structural steel connections, and heavy equipment assemblies. With partial threading and external hex drive, these fasteners offer optimal grip length while allowing for high torque application. The combination of 150,000 psi tensile strength and Rockwell C33 hardness makes these screws ideal for critical joints in construction, manufacturing, and transportation equipment where dynamic loads and stress concentrations are common.
Specification Summary & Compliance
This heavy-duty hex head screw features precise Class 2A thread fit with 3/8"-16 UNC coarse threading and 4 1/4" length. Manufactured to ASME B18.2.1 and SAE J429 Grade 8 specifications, ensuring dimensional accuracy and mechanical properties. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for global industrial applications with strict chemical substance restrictions.
