S-92805A544 1/4"-20 x 1 1/4" 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 in high-stress environments
• Superior corrosion resistance thanks to 18-8 stainless steel construction for extended service life in harsh conditions
• High tensile strength of 70,000 psi ensures reliable performance under heavy loads and mechanical stress
• Wide temperature tolerance from -65° to 250°F maintains locking integrity across extreme operating conditions
• Precision Class 3A thread fit provides consistent engagement and reliable fastening in critical applications
• 82° countersink angle enables flush mounting for streamlined assemblies and improved aesthetics
• Hex drive design delivers superior torque transmission and prevents tool slippage during installation

Professional Applications & Engineering Value

This nylon patch locking flat head screw addresses critical vibration-induced loosening challenges in industrial equipment, machinery, and transportation applications. The 18-8 stainless steel construction provides exceptional corrosion resistance for outdoor, marine, and chemical processing environments where moisture and corrosive elements are present. The permanent nylon patch locking technology creates consistent friction along the UNC coarse threads, eliminating the need for additional locking hardware while maintaining reliable performance across the broad temperature range from -65° to 250°F. The combination of 70,000 psi tensile strength and Rockwell B55 hardness ensures these fully threaded fasteners withstand dynamic loads and repeated stress cycles without compromising joint integrity, making them ideal for critical assemblies in aerospace, automotive, and heavy equipment manufacturing where vibration resistance and long-term reliability are paramount.

Specification Summary & Compliance

Manufactured to precise Class 3A thread fit tolerances with UNC 1/4"-20 coarse threading and standard 82° flat head profile. These screws conform to ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications, ensuring consistent quality and dimensional accuracy. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental and safety standards for industrial applications.