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Vacuum Grade Materials

AVT has extensive experience fabricating vacuum chambers and components using a variety of metals:

  • 300 series Stainless Steels (primarily 304 and 316)
  • Mu-metal 
  • Aluminum and Titanium
  • OFHC Copper
  • Nitronics, Inconel, Hastelloy and other specialty alloys
  • Molybdenum, Niobium, and other refractory metals

We will consider any material necessary for your requirements, and maintain complete material traceability from the mill to the finished product. Material Certifications are available for all jobs.  AVT can verify alloy compositions with our PMI (Positive Material Indicator) as needed.   


316LN-ESR Stainless Steel is produced using an electro-slag refinement process, and offers improved purity, homogeneity and corrosion resistance compared to typical 304/316 stainless steels. 

316 LN-ESR CF flanges 316L, heat-treated, MP gauge


AVT stocks 316LN-ESR bar material, as well as standard CF flanges to 6 inch diameter.  We can provide larger CF sizes, other flange types, or custom components by request. Flanges and components produced from 316LN-ESR grade material have superior mechanical properties compared to typical 304 and 316 grades flanges:

Material 304/316 SS 316LN-ESR SS
Maximum Temperature 450C 500C
Magnetic Permeability 1.1 to 1.4 <1.005
Hardness (Brinell) 140 to 150 170


Mu-metal is a nickel-iron alloy (77 % Ni, 15 % Fe, plus Cu and Mo) with extremely high magnetic permeability at low field strengths, and is an excellent material option for effective magnetic shielding. Stray magnetic fields can be an issue in certain vacuum systems, such as electron spectroscopy. Mu-Metal as an ideal material option for these applications.

An alternative to constructing complete chambers from mu-metal is to install multiple mu-metal liners inside the chamber.  This also helps reduce the effects of magnetic fields inside the vacuum system.  Applied Vacuum Technology has experience designing and fabricating custom chambers and shields from Mu-metal, and can help you consider critical design features and welds for your application. 


Request a quote today.  Let us know what AVT can provide for your application.