S-90507A209 4-40 Cap Nuts

Key Features & Benefits at a Glance

• Vibration-resistant locking through distorted thread design prevents loosening under dynamic loads
• Superior corrosion resistance with 18-8 stainless steel construction for harsh environments
• Precise Class 2B thread fit ensures smooth assembly and reliable engagement
• External hex drive provides excellent torque transmission and tool accessibility
• Coarse UNC threading enables faster installation and reduced cross-threading risk
• Full cap enclosure protects threads and creates finished appearance
• Regulatory compliance with RoHS 3 and REACH standards for global industrial use

Professional Applications & Engineering Value

This 4-40 UNC cap nut delivers critical vibration resistance where fastener integrity is paramount. The distorted thread locking technology creates permanent friction against mating threads, eliminating the need for secondary locking devices in machinery, automotive, and electrical enclosures. Manufactured from 18-8 stainless steel, it withstands corrosive environments while maintaining structural integrity. The external hex drive accommodates standard tools for efficient installation in confined spaces. With Class 2B thread fit precision, this locknut ensures consistent clamping force in assembly lines, reducing maintenance cycles and improving equipment reliability across industrial applications.

Specification Summary & Compliance

This cap nut features 4-40 UNC coarse threads with Class 2B fit tolerance, ensuring precise thread engagement. Dimensions include 1/4" width across flats and 1/4" height with 5/32" thread depth. The product complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting international environmental standards for industrial components. Right-hand thread direction and external hex drive style conform to industry-standard installation practices.