S-98070A141 4-40 x 1/2" Sealing Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior sealing performance with Buna-N rubber O-rings rated for up to 1500 psi pressure, preventing leaks in demanding applications
• Excellent corrosion resistance thanks to 18-8 stainless steel construction and passivated finish for extended service life
• Wide temperature compatibility with O-rings functioning reliably from -40° to 225° F for diverse operating environments
• Precise thread engagement with Class 2A UNC coarse threads ensuring consistent, reliable fastening in industrial assemblies
• Streamlined installation featuring Phillips #1 drive and undercut flat head design for flush mounting and reduced assembly time
• High tensile strength of 70,000 psi providing dependable mechanical performance under load
• Environmental compliance meeting RoHS 3 and REACH standards for safe use in regulated industries

Professional Applications & Engineering Value

Engineered for critical sealing applications, these 4-40 UNC flat head screws solve common industrial challenges where fluid containment and pressure management are paramount. The combination of 18-8 stainless steel with passivated finish provides exceptional resistance to corrosion in harsh environments, while the Buna-N rubber O-ring creates a reliable seal against moisture, gases, and contaminants. The undercut flat head profile ensures proper countersinking and flush installation, preventing interference in precision assemblies. These sealing screws are particularly valuable in equipment requiring pressure containment up to 1500 psi, making them ideal for hydraulic components, pneumatic systems, and industrial machinery where leak prevention is critical to operational safety and efficiency.

Specification Summary & Compliance

This fastener features Class 2A thread fit with UNC coarse threading (4-40 size) and fully threaded design for maximum engagement. Manufacturing complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The passivated finish enhances corrosion resistance while maintaining dimensional accuracy with 100° countersink angle and 0.129" maximum hole diameter compatibility.