S-95198A277 4-40 x 5/8" ASME B18.3, DIN 912, ISO 4762 Sealing Socket Head Screws

Key Features & Benefits at a Glance

• Superior sealing performance with integrated Buna-N rubber O-ring to prevent fluid and gas leaks in demanding applications
• Exceptional corrosion resistance from 18-8 stainless steel construction for long-term reliability in harsh environments
• High-pressure capability withstands up to 1500 psi, ensuring secure fastening in hydraulic and pneumatic systems
• Precise thread engagement with Class 3A fit for superior vibration resistance and reduced loosening risks
• Wide temperature tolerance maintains sealing integrity from -40° to 225°F across diverse operating conditions
• High strength construction delivers 100,000 psi tensile strength and Rockwell B85 hardness for heavy-duty applications
• Standardized compatibility with hex drive tools for consistent installation and maintenance procedures

Professional Applications & Engineering Value

This 4-40 UNC thread socket head cap screw provides critical sealing solutions for industrial equipment where pressure integrity is paramount. The 18-8 stainless steel construction combined with the Buna-N rubber O-ring creates a reliable barrier against fluid and gas penetration in hydraulic systems, pneumatic controls, and precision instrumentation. Engineers specify this fastener for applications requiring both high-pressure resistance up to 1500 psi and consistent performance across extreme temperature ranges from -40° to 225°F. The Class 3A thread fit ensures precise engagement that minimizes vibration-induced loosening in dynamic assemblies, while the standardized hex drive design facilitates efficient installation in confined spaces common in machinery and equipment manufacturing.

Specification Summary & Compliance

This sealing socket head cap screw features 4-40 UNC coarse threads with Class 3A fit for precision engagement, manufactured to ASME B18.3, DIN 912, and ISO 4762 standards. The fastener maintains dimensional accuracy with a 5/8" length and fully threaded design. Compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental and safety standards are met for industrial applications worldwide.