S-99291A340 5/16"-18 Locknuts
Locknuts
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Basic Information
Dimension Parameters
Thread Parameters
Head Parameters
Material & Strength Parameters
Installation & Application Parameters
Finish & Compliance Parameters
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Key Features & Benefits at a Glance
- Superior vibration resistance through distorted thread locking technology that maintains secure fastening under dynamic loads
- Enhanced corrosion protection with black-oxide steel finish for extended service life in harsh industrial environments
- Reliable thread engagement with Class 2B thread fit ensuring precise mating and consistent performance
- High-strength construction meeting ASTM Grade C specifications for demanding applications
- Easy installation and removal with standard external hex drive design compatible with common tools
- Environmental compliance with REACH and RoHS 3 standards for safe industrial use
- Optimized locking performance through top lock distorted thread design that resists loosening
Professional Applications & Engineering Value
This 5/16"-18 UNC locknut delivers critical vibration resistance in industrial machinery, automotive assemblies, and heavy equipment where constant motion threatens fastener integrity. The distorted thread locking mechanism creates consistent interference that prevents spontaneous loosening, eliminating the need for secondary locking devices. Manufactured from black-oxide steel, the nut provides superior corrosion resistance while maintaining the structural integrity required for ASTM Grade C applications. The coarse UNC thread profile ensures rapid installation and reliable performance in high-vibration environments, making it ideal for construction equipment, agricultural machinery, and transportation systems where maintenance access may be limited.
Specification Summary & Compliance
This locknut features 5/16"-18 UNC coarse threads with Class 2B thread fit tolerance for precision engagement. The standard hex profile measures 1/2" across flats with a height of 17/64". Manufactured to ASTM Grade C specifications with right-hand thread direction and top lock distorted thread design. Fully compliant with REACH (EC 1907/2006) and RoHS 3 (2015/863/EU) environmental standards for industrial safety requirements.
