S-91257A647 3/8"-16 x 5 3/4" 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 tensile strength of 150,000 PSI ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
- Superior corrosion resistance from zinc yellow-chromate plating extends service life in harsh or outdoor environments.
- High hardness rating (Rockwell C33) provides excellent wear resistance and durability under repetitive loads.
- Coarse UNC threading allows for quicker installation and better performance in materials prone to vibration or thermal expansion.
- Partially threaded design offers optimal clamping force and prevents loosening in dynamic assemblies.
- External hex drive enables easy installation and removal with standard tools, improving maintenance efficiency.
- Compliance with ASME B18.2.1 and SAE J429 guarantees consistent quality and interchangeability in industrial systems.
Professional Applications & Engineering Value
This Grade 8 hex head screw is engineered to address critical challenges in heavy machinery, construction, and automotive assemblies where vibration, high loads, and environmental exposure are common. The steel material combined with zinc yellow-chromate plating provides a robust barrier against rust and chemical degradation, ensuring long-term reliability in demanding conditions. The 3/8"-16 UNC coarse thread enhances grip in soft or composite materials, reducing the risk of stripping. Its partially threaded shank concentrates clamping force precisely where needed, minimizing stress concentration and improving joint integrity. Ideal for structural frames, engine components, and industrial equipment, this fastener delivers consistent performance under 150,000 PSI tensile strength, meeting rigorous engineering standards for safety and durability.
Specification Summary & Compliance
This screw adheres to Class 2A thread fit for consistent assembly and interchangeability. It conforms to ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and mechanical properties. The zinc yellow-chromate finish meets industry standards for corrosion protection, while the material and manufacturing processes comply with relevant industrial regulations for quality assurance.
