S-91286A338 1/2"-13 x 3 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 reliable performance in high-stress applications.
- Superior corrosion resistance provided by zinc-flake coating, extending service life in harsh industrial environments.
- High hardness rating of Rockwell C33 ensures minimal wear and deformation under heavy use.
- Secure fastening with Class 2A thread fit for precise engagement and reduced risk of loosening in vibrating machinery.
- Easy installation and removal with standard 3/4" external hex head design, compatible with common tools.
- Optimized for coarse threading (UNC) enabling quicker assembly and better performance in softer materials or where debris is present.
- Partially threaded shank allows for controlled clamping force and reduced thread damage during repeated use.
Professional Applications & Engineering Value
Engineered for demanding industrial settings, this Grade 8 hex head screw combines high-strength steel construction with a zinc-flake coated finish to combat rust and chemical exposure in outdoor or corrosive environments. The 1/2"-13 UNC coarse thread and partial threading design provide rapid installation and secure holding power in structural assemblies, heavy machinery, and construction projects. Its 150,000 psi tensile strength and Rockwell C33 hardness address common failure points like shear and fatigue, ensuring long-term reliability in applications such as equipment frames, automotive components, and infrastructure fastening where vibration resistance and durability are critical.
Specification Summary & Compliance
This screw adheres to Class 2A thread fit tolerances and meets ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and mechanical properties. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material restrictions are met for global industrial use.
