S-91257A851 3/4"-10 x 4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws
High-Strength Grade 8 Steel Hex Head Screws
Image may differ from product. See technical specification for details.
Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
- Fast delivery
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
Key Features & Benefits at a Glance
- Exceptional load-bearing capacity with 150,000 psi tensile strength and Grade 8 classification for reliable performance in demanding applications.
- Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in harsh industrial environments.
- Optimized thread engagement through UNC coarse threading and Class 2A thread fit for faster assembly and secure fastening.
- Enhanced torque transmission with external hex drive and 1 1/8" head width for easy installation using standard tools.
- Controlled thread placement with partial threading design for precise clamping force distribution.
- High hardness rating of Rockwell C33 ensuring excellent wear resistance and durability under vibration.
- Regulatory compliance assurance meeting ASME B18.2.1, SAE J429 standards plus RoHS 3 and REACH environmental directives.
Professional Applications & Engineering Value
These Grade 8 hex head screws deliver critical reliability for heavy machinery, structural steel connections, and industrial equipment where high tensile strength and vibration resistance are paramount. The zinc yellow-chromate plating creates a protective barrier against oxidation and chemical exposure, significantly extending maintenance intervals in corrosive environments. With UNC coarse threads and Class 2A thread fit, these fasteners provide rapid installation while maintaining precise tolerances. The partially threaded design concentrates clamping force exactly where needed, preventing joint loosening in dynamic applications. Engineered to ASME B18.2.1 and SAE J429 specifications, these screws offer predictable performance for critical bolting applications across construction, manufacturing, and transportation sectors.
Specification Summary & Compliance
This 3/4"-10 hex head screw features Class 2A thread fit per UNC standards with 4" length and 1 3/4" minimum thread length. Manufactured to ASME B18.2.1 and SAE J429 Grade 8 requirements with 150,000 psi tensile strength and Rockwell C33 hardness. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for industrial use.
