S-92805A535 1/4"-20 x 3/8" ASME B18.3, ASTM F879, MIL-DTL-18240 Stainless Steel Thread-Locking Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with permanent Nylon patch that maintains secure fastening from -65° to 250°F
• Superior corrosion resistance thanks to 18-8 Stainless Steel construction for extended service life in harsh environments
• High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness for demanding applications
• Precise thread engagement with Class 3A UNC coarse threads ensuring reliable fit and reduced cross-threading risk
• Secure hex drive installation using standard 5/32" tools for consistent torque application and reduced stripping
• Flush mounting capability with standard 82° countersink angle for smooth surface finishes
• Full-threaded design providing maximum grip length and holding power throughout the entire fastener

Professional Applications & Engineering Value

This nylon patch locking flat head screw delivers exceptional engineering value in vibration-resistant applications where secure fastening is critical. The 18-8 Stainless Steel construction provides outstanding corrosion resistance, making it ideal for harsh industrial environments, marine applications, and outdoor equipment. The permanent nylon patch locking mechanism eliminates the need for additional locking hardware while maintaining reliability across a wide temperature range from -65° to 250°F. The Class 3A UNC coarse threads ensure quick installation and superior resistance to vibration loosening in machinery, automotive assemblies, and electronic enclosures. The hex drive design allows for high-torque installation without slippage, while the flat head profile with 82° countersink provides a clean, flush finish for applications where surface protrusion cannot be tolerated.

Specification Summary & Compliance

This fastener features Class 3A thread fit for precision engagement and meets ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications. The UNC coarse thread (1/4"-20) with fully threaded design ensures maximum holding strength. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations guarantees environmental safety and regulatory adherence for global industrial applications.