S-98164A437 5-40 x 3/8" ASME B18.3 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance in harsh environments thanks to 316 stainless steel construction with passivated finish
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for reliable load-bearing performance
• Precise thread engagement with Class 3A fit and UNC coarse threading ensuring vibration resistance and secure fastening
• Full-length threading provides maximum grip and consistent holding power across the entire fastener length
• Easy installation and removal with 5/64" hex drive design offering positive tool engagement and reduced stripping risk
• Rounded button head profile creates a low-profile, aesthetically pleasing finish while minimizing snag hazards
• Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

These 316 stainless steel rounded head screws deliver exceptional performance in demanding industrial environments where corrosion resistance and mechanical reliability are critical. The combination of UNC coarse threading with Class 3A fit ensures rapid assembly and superior vibration resistance in machinery, electrical enclosures, and marine applications. The passivated finish enhances the natural corrosion resistance of 316 stainless steel, making these hex drive screws ideal for chemical processing, food manufacturing, and outdoor equipment where exposure to moisture and aggressive substances is common. The fully threaded design provides consistent clamping force across the entire engagement length, eliminating weak points in critical assemblies.

Specification Summary & Compliance

This 5-40 UNC 3/8" screw features precise Class 3A thread fit with coarse thread spacing, manufactured to exacting ASME B18.3 specifications. The fastener maintains dimensional accuracy with 0.125" thread diameter, 0.238" head diameter, and consistent 5/64" hex drive compatibility. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations ensures environmental responsibility, while the 70,000 psi tensile strength and Rockwell B55 hardness guarantee mechanical performance in industrial applications.