S-93310A334 1/4"-20 x 1/4" ASME B18.3, ASTM F879, MIL-DTL-18240 Thread-Locking Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Permanent vibration resistance with nylon patch locking that maintains secure fastening in high-stress environments
• Superior corrosion resistance from 18-8 stainless steel construction for extended service life in harsh conditions
• 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 installation and load distribution
• Wide temperature tolerance from -70° to 250°F for stable performance across diverse operating environments
• Secure hex drive installation with 5/32" drive size providing positive torque control and reduced cam-out risk
• Full thread coverage along the entire 1/4" length for maximum grip and fastener integrity

Professional Applications & Engineering Value

These 1/4"-20 UNC nylon patch locking screws deliver critical vibration resistance where traditional fasteners fail. The permanent nylon patch locking technology creates consistent friction that prevents loosening under dynamic loads, making them ideal for industrial machinery, automotive assemblies, and electronic enclosures. Manufactured from 18-8 stainless steel, they provide excellent corrosion resistance while maintaining 70,000 psi tensile strength for structural integrity. The rounded button head profile combines aesthetic appeal with functional clearance, while the hex drive design ensures reliable installation torque. These fully threaded screws with Class 3A thread fit offer precise engagement for applications requiring repeated disassembly and reassembly without compromising locking performance.

Specification Summary & Compliance

This rounded head screw features precise Class 3A thread fit with UNC coarse threading (1/4"-20) and meets ASME B18.3, ASTM F879, and MIL-DTL-18240 manufacturing specifications. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets. Dimensions include 0.437" head diameter, 1/4" length, and 5/32" hex drive size for standardized installation.