S-98164A438 5-40 x 1/2" ASME B18.3 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance thanks to 316 stainless steel construction and passivated finish, ideal for harsh industrial environments
• High mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for reliable, long-term performance under load
• Precise, secure fastening ensured by Class 3A thread fit and UNC coarse threading, reducing cross-threading risks
• Easy installation and removal with 5/64" hex drive, providing excellent torque transmission and tool engagement
• Full thread engagement across the 1/2" length for maximum grip and load distribution in assemblies
• Compliance with major standards including ASME B18.3, RoHS 3, and REACH, ensuring regulatory acceptance and material safety
• Rounded button head design offers a low-profile, finished appearance while minimizing snagging and user injury

Professional Applications & Engineering Value

These 316 stainless steel rounded head screws with 5-40 UNC coarse threading are engineered to address critical challenges in demanding applications. The combination of high tensile strength (70,000 psi) and exceptional corrosion resistance makes them ideal for marine, chemical processing, and food industry equipment where moisture and corrosive agents are prevalent. The passivated finish enhances surface durability, while the fully threaded design ensures uniform stress distribution and vibration resistance. Their hex drive and Class 3A thread fit provide reliable, repeatable fastening in automated assembly lines, reducing installation time and maintenance costs. These screws deliver consistent performance in structural frameworks, machinery, and electronic enclosures, meeting rigorous industrial screw requirements.

Specification Summary & Compliance

This product features precise Class 3A thread fit with 5-40 UNC coarse threads, manufactured to ASME B18.3 specifications for dimensional accuracy. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and restricted substance adherence. The screw is fully threaded with a length of 1/2", head diameter of 0.238", and 5/64" hex drive, providing consistent performance in regulated industrial applications.