S-91257A493 1/2"-20 x 8" 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 capability with 150,000 PSI tensile strength and Rockwell C33 hardness for reliable performance in high-stress industrial environments.
- Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in harsh or outdoor conditions.
- Precise thread engagement with Class 2A fit and UNF fine threading, ensuring secure fastening and vibration resistance.
- Heavy-duty Grade 8 classification guarantees consistent mechanical properties for critical structural applications.
- Optimized torque transmission through external hex drive and 3/4" head width, facilitating easy installation with standard tools.
- Versatile partial threading on a 8" length allows for both clamping and alignment functions in assembled components.
- Full regulatory compliance with ASME B18.2.1, SAE J429, RoHS 3, and REACH standards for global industrial use.
Professional Applications & Engineering Value
Engineered for heavy-duty industrial applications, these Grade 8 hex head screws deliver uncompromising reliability where structural integrity is paramount. The 1/2"-20 UNF fine thread configuration provides superior resistance to loosening under dynamic loads, while the zinc yellow-chromate plating creates a robust barrier against corrosion in manufacturing, construction, and machinery assembly. The partially threaded design enables precise clamping force distribution across connected materials, making these steel fasteners ideal for structural steel connections, heavy equipment maintenance, and infrastructure projects requiring 150,000 PSI tensile strength. Their compliance with ASME B18.2.1 specifications ensures dimensional consistency and interchangeability in critical bolted joints.
Specification Summary & Compliance
This 8" hex head screw maintains Class 2A thread fit tolerances per UNF standards with 1/2"-20 fine threading and partial threading over 1 1/2" minimum length. Manufactured to ASME B18.2.1 and SAE J429 Grade 8 requirements, it demonstrates full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations.
