S-93310A537 1/4"-20 x 1/2" 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 through nylon patch locking technology, ensuring secure fastening in high-stress environments
• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial applications
• High tensile strength of 70,000 psi provides reliable performance under heavy mechanical loads
• Wide temperature tolerance from -70° to 250°F maintains locking integrity across extreme operating conditions
• Precision Class 3A thread fit ensures smooth installation and optimal engagement with mating components
• Hex drive design allows for high-torque installation with standard tools, reducing assembly time
• Rounded button head profile offers a low-profile, aesthetically pleasing finish while minimizing snag hazards

Professional Applications & Engineering Value

This 18-8 stainless steel rounded head screw with nylon patch locking technology addresses critical vibration-induced loosening challenges in industrial equipment, machinery, and automotive assemblies. The coarse UNC thread design provides excellent engagement in various materials, while the Class 3A thread fit ensures precise installation without cross-threading risks. The combination of 70,000 psi tensile strength and Rockwell B55 hardness delivers exceptional durability for demanding applications where fastener failure is not an option. The hex drive configuration enables efficient installation in confined spaces, making these vibration resistant screws ideal for maintenance-critical systems requiring reliable, long-term fastening solutions.

Specification Summary & Compliance

Manufactured to exacting standards including ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications. Features precision Class 3A thread fit with 1/4"-20 UNC coarse threads and right-hand threading. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The nylon patch lock maintains performance across the specified temperature range of -70° to 250°F, ensuring reliable operation in diverse industrial environments.