S-99851A101 4-40 MS21046C04, NASM21046 Locknuts
Locknuts
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Basic Information
Dimension Parameters
Thread Parameters
Head Parameters
Material & Strength Parameters
Finish & Compliance Parameters
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Key Features & Benefits at a Glance
- Superior vibration resistance with flex-top locking design for secure, long-lasting fastening in high-stress environments
- Enhanced corrosion protection through silver-plated 18-8 stainless steel construction for extended service life
- Precision Class 3B thread fit ensures reliable engagement and consistent clamping force in critical assemblies
- External hex drive compatibility enables quick installation with standard tools while maintaining structural integrity
- Compliance with MS21046C04/NASM21046 specifications guarantees aerospace-grade quality and performance consistency
- RoHS 3 and REACH environmental compliance meets stringent regulatory requirements for industrial applications
- Coarse UNC threading provides rapid assembly and disassembly while maintaining secure locking capability
Professional Applications & Engineering Value
Engineered for demanding aerospace and industrial applications, this 4-40 UNC locknut combines silver-plated 18-8 stainless steel with an innovative flex-top locking mechanism to solve critical vibration-induced loosening problems. The external hex drive allows for efficient installation in confined spaces while maintaining torque integrity. The Class 3B thread fit ensures precise engagement with mating components, eliminating play and maintaining clamp load under extreme conditions. This MS21046C04 and NASM21046 compliant fastener delivers reliable performance in critical assemblies where failure is not an option, from aircraft control systems to precision industrial machinery requiring vibration-resistant locking solutions.
Specification Summary & Compliance
This 4-40 UNC thread locknut features Class 3B thread fit precision and coarse thread spacing for optimal performance. Manufactured to meet MS21046C04 and NASM21046 specifications with right-hand thread direction and standard external hex drive configuration. The product is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, ensuring environmental responsibility while maintaining the highest engineering standards for industrial and aerospace applications.
