Stainless Steel Vacuum Flange Plate 4" OD 4-1/8" Center 1/2" ID Port

Stainless Steel Vacuum Flange Plate 4" OD 4-1/8" Center 1/2" ID Port

This is a solid stainless steel vacuum flange plate featuring a center bore port and multiple countersunk mounting holes arranged on a bolt circle pattern. The part is machined from stainless steel and is designed for use as a port cover, blanking plate, or feedthrough mounting plate in vacuum chamber assemblies. No brand markings or part numbers are present on the part.

Specifications & What's Included

• Material: Stainless steel (machined)
• Outer diameter (OD): approximately 4 inches
• Center port inner diameter (ID): approximately 1/2 inch
• Bolt circle diameter: approximately 4-1/8 inches
• Multiple countersunk mounting holes visible on face
• Finish: machined/turned face with brushed stainless appearance
• No brand markings or model numbers present
• Flange plate only — no additional hardware included

Applications

Stainless steel vacuum flange plates like this one are standard components in vacuum chamber systems used across semiconductor processing, thin-film deposition (PVD/CVD), surface science research, and general laboratory vacuum work. They are used to blank off unused ports, mount feedthroughs or sensors, or serve as custom access plates on vacuum vessels and bell jars. Stainless steel is the preferred material for high-vacuum and ultra-high-vacuum (UHV) applications because of its low outgassing rate, corrosion resistance, and compatibility with standard vacuum sealing methods. This type of plate is commonly found in research labs, university physics and chemistry departments, semiconductor fabs, and industrial coating systems.