S-91211A229 3/4"-10 x 3 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Thread-Locking Hex Head Screws
High-Strength Grade 8 Steel Thread-Locking 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
- Vibration-resistant locking with nylon patch thread locker prevents loosening under dynamic loads, maintaining joint integrity from -55° to 250° F
- Exceptional load-bearing capacity with 150,000 PSI tensile strength and Grade 8 classification for critical structural applications
- Superior corrosion protection through zinc yellow-chromate plating that withstands harsh industrial environments
- Optimized torque transmission via external hex drive and 1 1/8" head width for secure installation with standard tools
- Reliable thread engagement with Class 2A thread fit and UNC coarse threading ensuring consistent assembly performance
- Enhanced durability with Rockwell C33 hardness providing excellent resistance to wear and deformation
- Controlled thread engagement through partial threading design for precise load distribution
Professional Applications & Engineering Value
Engineered for demanding industrial fastening scenarios, these Grade 8 hex head screws address critical vibration-induced failure points through their integrated nylon patch thread locker. The zinc yellow-chromate plated steel construction delivers superior corrosion resistance in manufacturing environments, while the 150,000 PSI tensile strength and Rockwell C33 hardness ensure reliable performance under extreme mechanical stress. The 3/4"-10 UNC coarse thread configuration provides rapid assembly in heavy equipment, structural steel connections, and machinery where external hex drive accessibility is essential for maintenance operations. These partially threaded fasteners concentrate strength where needed most, making them ideal for high-strength bolting applications requiring precise clamp load distribution.
Specification Summary & Compliance
Manufactured to ASME B18.2.1 and SAE J429 Grade 8 specifications with Class 2A thread fit tolerance. Features 3/4"-10 UNC coarse threads with 1 3/4" minimum thread length on a 3 1/2" overall length. The nylon patch thread locker operates within -55° to 250° F temperature range. Complies with RoHS and REACH environmental standards for industrial use.
