S-93310A640 3/8"-16 x 3/4" ASME B18.3, ASTM F879, MIL-DTL-18240 Thread-Locking Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with permanent nylon patch that maintains integrity across a wide temperature range from -70°F to 250°F
• Superior corrosion resistance thanks to 18-8 stainless steel construction, ideal for harsh industrial environments
• High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness for demanding applications
• Precise thread engagement with Class 3A fit ensuring reliable fastening and reduced risk of cross-threading
• Easy installation and removal with hex drive design providing superior torque transmission and tool compatibility
• Optimized load distribution through rounded button head profile that minimizes surface damage
• Full thread coverage along the entire 3/4" length for maximum grip strength and adjustment flexibility

Professional Applications & Engineering Value

This nylon patch locking rounded head screw delivers exceptional value in applications where vibration resistance and environmental durability are critical. The 18-8 stainless steel construction provides excellent corrosion resistance for outdoor equipment, marine applications, and chemical processing environments. The permanent nylon patch thread locker eliminates the need for separate locking washers or adhesives, streamlining assembly while maintaining secure fastening across extreme temperature fluctuations from -70°F to 250°F. The coarse UNC threads with Class 3A precision ensure quick installation and reliable performance in high-vibration machinery, automotive assemblies, and industrial equipment where thread integrity cannot be compromised. The combination of hex drive compatibility and rounded button head profile allows for both high-torque installation and clean aesthetic finish in visible applications.

Specification Summary & Compliance

This fastener features 3/8"-16 UNC coarse threads with Class 3A thread fit for precision engagement and meets ASME B18.3, ASTM F879, and MIL-DTL-18240 manufacturing specifications. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets. With fully threaded design and standardized dimensions including 0.656" head diameter and 7/32" hex drive size, this screw delivers consistent performance and interchangeability in professional applications.