S-91257A567 1/4"-28 x 1 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 load-bearing capability with 150,000 psi tensile strength for reliable performance in high-stress applications
- Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in harsh environments
- Precise thread engagement with Class 2A fit and UNF fine threading for secure fastening and vibration resistance
- Optimized partial threading design allowing for focused clamping force where needed most
- Heavy-duty Grade 8 classification ensuring consistent mechanical properties and Rockwell C33 hardness
- External hex drive compatibility for standard tooling and efficient installation
- Regulatory compliance assurance meeting ASME, SAE, RoHS 3, and REACH standards for quality and safety
Professional Applications & Engineering Value
This Grade 8 hex head screw delivers critical engineering solutions for heavy-duty industrial applications where failure is not an option. The combination of high-strength steel material and zinc yellow-chromate plating addresses common challenges of structural integrity and environmental degradation in machinery, construction, and automotive assemblies. The 1/4"-28 UNF fine thread configuration provides superior resistance to loosening under vibration, while the partially threaded design concentrates clamping force precisely where needed. With 150,000 psi tensile strength and Rockwell C33 hardness, this fastener maintains performance in demanding conditions where standard fasteners would compromise system reliability.
Specification Summary & Compliance
Manufactured to precise dimensional standards with Class 2A thread fit tolerance and UNF thread form ensuring consistent performance across applications. This 1/4"-28 hex head screw complies with ASME B18.2.1 and SAE J429 Grade 8 specifications for mechanical properties and dimensional requirements. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) regulations for chemical safety, providing assurance for use in regulated industries and international markets.
