S-91257A770 9/16"-12 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 demanding applications
- Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in harsh environments
- Optimized torque transmission through the external hex drive design for secure installation and removal
- Enhanced thread engagement with Class 2A thread fit ensuring precise assembly and vibration resistance
- Reduced cross-threading risk through UNC coarse threading for faster installation in industrial settings
- Partial threading design allows for both clamping and alignment functions in structural applications
- Industry compliance assurance meeting ASME B18.2.1 and SAE J429 standards for quality and reliability
Professional Applications & Engineering Value
These Grade 8 hex head screws deliver exceptional engineering value in heavy machinery, construction equipment, and structural steel applications where high tensile strength and corrosion resistance are critical. The zinc yellow-chromate plating provides superior protection against environmental degradation, while the 9/16"-12 UNC coarse threading ensures rapid assembly in thick materials and reduces the risk of cross-threading during high-volume production. The partially threaded design offers optimal clamping force distribution, making these industrial hex screws ideal for applications requiring both precise alignment and secure fastening. With Rockwell C33 hardness, these fasteners maintain integrity under extreme mechanical stress and vibration, solving common failure points in heavy-duty equipment.
Specification Summary & Compliance
Manufactured to precise dimensional standards with Class 2A thread fit tolerance for consistent performance. Complies with ASME B18.2.1 and SAE J429 specifications for Grade 8 fasteners. Meets environmental regulations including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance standards. Features 9/16"-12 UNC coarse threading with partial threading extending to minimum 1-3/8" thread length.
