S-90841A110 4-40 x 1/2" ASME B18.3 High-Vacuum Cleaned-and-Bagged Vented Socket Head Screws

Key Features & Benefits at a Glance

• Superior vacuum performance with vented design (0.036" vent diameter) prevents outgassing and ensures reliable operation in high-vacuum environments
• Exceptional corrosion resistance from 18-8 stainless steel construction maintains integrity in harsh industrial conditions
• High-strength reliability with 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Precision thread engagement with Class 3A UNC coarse threads ensures secure fastening and vibration resistance
• Easy installation and removal using standard 3/32" hex drive for efficient maintenance and assembly
• Full regulatory compliance meets ASME B18.3 standards and environmental regulations (RoHS 3, REACH)
• Versatile fully-threaded design provides consistent holding power across the entire 1/2" length

Professional Applications & Engineering Value

This high-vacuum rated socket head cap screw solves critical engineering challenges in precision industries where contamination control and reliability are paramount. The 18-8 stainless steel construction combined with the specialized vented design prevents trapped air and outgassing that can compromise vacuum integrity in semiconductor manufacturing, analytical instrumentation, and aerospace systems. The Class 3A UNC coarse threads deliver superior engagement in materials where fine threads might strip, while the fully threaded configuration ensures maximum clamping force distribution. With 70,000 psi tensile strength and corrosion-resistant properties, this fastener maintains performance in demanding environments where standard screws would fail, making it ideal for vacuum chambers, scientific equipment, and high-precision mechanical assemblies requiring repeated maintenance access.

Specification Summary & Compliance

This precision socket head cap screw features 4-40 UNC coarse threads with Class 3A thread fit for superior dimensional accuracy. The 1/2" fully threaded design maintains strict adherence to ASME B18.3 manufacturing specifications. Environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) certifications, ensuring safe use in regulated industries. The combination of precise thread geometry, material certification, and specialized venting makes this fastener suitable for high-reliability applications where performance standards cannot be compromised.