S-93310A333 1/4"-20 x 3/16" 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 thread locker prevents loosening under dynamic loads, ensuring long-term assembly integrity.
• Superior corrosion resistance from 18-8 Stainless Steel construction maintains performance in humid or chemically aggressive environments.
• High-strength reliability with 70,000 psi tensile strength and Rockwell B55 hardness for demanding mechanical applications.
• Precise thread engagement with Class 3A fit and UNC coarse threads enables quick installation and secure fastening.
• Wide temperature tolerance from -70° to 250°F allows consistent performance in extreme operating conditions.
• Tool-friendly installation using a standard 5/32" hex drive for efficient assembly with common industrial tools.
• Regulatory compliance with RoHS 3 and REACH ensures environmental safety and global market acceptance.

Professional Applications & Engineering Value

This 1/4-20 UNC screw with Nylon Patch lock is engineered to solve critical vibration-induced loosening in industrial assemblies. The 18-8 Stainless Steel material provides excellent corrosion resistance, making it ideal for outdoor equipment, marine hardware, and food processing machinery where moisture exposure is common. The rounded button head design offers a low-profile finish while the fully threaded construction ensures maximum grip length in thin materials. With its Class 3A thread fit and coarse threading, this hex drive screw delivers reliable performance in high-vibration applications such as automotive components, machinery guards, and electrical enclosures, where maintaining clamp force is essential for operational safety.

Specification Summary & Compliance

This rounded head screw features precise Class 3A thread fit with UNC 1/4"-20 coarse threads 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 adherence to international standards for hazardous substance restrictions.