S-92805A537 1/4"-20 x 1/2" ASME B18.3, ASTM F879, MIL-DTL-18240 Stainless Steel Thread-Locking Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior vibration resistance with nylon patch thread locker that maintains integrity from -65° to 250°F, preventing loosening in dynamic environments
• Exceptional corrosion resistance from 18-8 stainless steel construction, ideal for harsh industrial conditions and outdoor applications
• High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness for reliable load-bearing capability
• Precise thread engagement with Class 3A thread fit ensuring tight tolerances and secure fastening in critical assemblies
• Easy installation and removal with standard hex drive (5/32") providing positive torque transmission and reduced tool slippage
• Optimized flush mounting with 82° countersink angle and flat head design for smooth surface finishes
• Full threading coverage along the entire 1/2" length for maximum grip strength and uniform stress distribution

Professional Applications & Engineering Value

These 18-8 stainless steel flat head screws with nylon patch locking technology deliver critical vibration resistance in demanding industrial applications where secure fastening is paramount. The coarse UNC 1/4"-20 threading combined with Class 3A thread fit ensures rapid assembly and reliable performance in machinery, automotive components, and electronic enclosures subject to constant movement and thermal cycling. The hex drive configuration provides superior torque transmission during installation, while the temperature-resistant nylon patch thread locker (-65° to 250°F) maintains clamping force integrity in environments where thermal expansion and vibration would compromise standard fasteners. This combination of materials and engineering makes these flat head screws ideal for aerospace, military, and precision manufacturing applications requiring dependable, long-term fastening solutions.

Specification Summary & Compliance

Manufactured to Class 3A thread fit tolerances with UNC 1/4"-20 coarse threading and right-hand thread direction. Complies with ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications for dimensional accuracy and performance. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards. Features standard 82° countersink angle, fully threaded 1/2" length, and manufactured from 18-8 stainless steel with Rockwell B55 hardness and 70,000 psi tensile strength.