S-95198A128 4-40 x 1/4" ASME B18.3, DIN 912, ISO 4762 Sealing Socket Head Screws

Key Features & Benefits at a Glance

• Superior sealing performance with integrated silicone rubber O-ring, effectively preventing leaks in high-pressure applications up to 1500 psi.
• Exceptional corrosion resistance due to 18-8 stainless steel construction, ensuring long-term reliability in harsh industrial environments.
• High mechanical strength with 100,000 psi tensile strength and Rockwell B85 hardness, providing reliable fastening under heavy loads.
• Precise thread engagement with Class 3A UNC coarse threads, enabling quick assembly and secure, vibration-resistant connections.
• Wide temperature tolerance from -80° to 400°F, maintaining sealing integrity and performance across extreme operating conditions.
• Standard hex drive compatibility with 3/32" drive size, allowing for easy installation and removal with common industrial tools.
• Full regulatory compliance with ASME B18.3, DIN 912, and ISO 4762 standards, ensuring interchangeability and global engineering acceptance.

Professional Applications & Engineering Value

This 4-40 UNC thread socket head cap screw delivers critical sealing capability in demanding industrial applications where fluid or gas containment is essential. The 18-8 stainless steel body provides excellent corrosion resistance, while the integrated silicone rubber O-ring creates a reliable seal against pressures up to 1500 psi. The Class 3A thread fit ensures precise engagement with mating components, reducing the risk of cross-threading and providing vibration resistance in dynamic environments. These features make it ideal for hydraulic systems, pneumatic equipment, and precision machinery where leak prevention and structural integrity are paramount. The combination of high tensile strength and temperature resistance from -80° to 400°F ensures consistent performance across diverse operating conditions, from cryogenic applications to high-temperature industrial processes.

Specification Summary & Compliance

This socket head cap screw features 4-40 UNC coarse threads with Class 3A precision fit for optimal engagement and vibration resistance. Manufactured to ASME B18.3, DIN 912, and ISO 4762 standards, ensuring dimensional accuracy and interchangeability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, meeting current environmental and safety requirements for industrial components.