SilcoNert, Sulfinert, Silcosteel, Siltek… What’s the Difference?

August 05 2022 SilcoTek

Assorted sampling components coated with SilcoNert® 2000.Assorted sampling components coated with SilcoNert® 2000.


SilcoNert, Sulfinert, Silcosteel, Siltek… What’s the Difference?



Whether you’ve been involved in chromatography for days or decades, you understand the importance of reducing the negative effects that bare metals have on your samples. Stainless steel is generally a preferred material of construction for analytical sampling systems due to its relatively good chemical and corrosion resistance, but it is highly prone to adsorbing reactive sample media like sulfur compounds (especially H2S), mercury, ammonia, and many others. As sampling applications become increasingly demanding and require lower detection limits, chemically inert flow path materials have never been more important.

SilcoTek® is the chromatography industry’s leading innovator and service provider in advanced coatings that render stainless steel chemically inert. Founding SilcoTek employees first developed Silcosteel® as part of Restek® in the late 1980s for metal GC capillary columns. Today, SilcoTek’s SilcoNert® 2000 coating has become the standard for ensuring reliable trace chemical analysis in oil and gas wells, refineries, air quality laboratories, and many other applications. Between now and then, brand names like Sulfinert® and Siltek® have emerged.

You are not alone if you have asked, “what is the difference between these coatings, and which one is the best for my application?” This blog article answers these questions.


First, a brief history timeline of SilcoTek’s coating technologies:

Paul-Restek-LabRestek founder, Paul Silvis, in the late 1980s.

  • 1987: 2 years after founding Restek, Paul Silvis and a team of Restek scientists invent Silcosteel® for metal GC capillaries as an alternative to glass capillaries. They utilize chemical vapor deposition (CVD), a special application technique that enables efficient coating of high aspect ratios and complex product geometries.

  • 1990-2000: customers request Silcosteel® on a custom basis for a variety of sampling components. A dedicated team is formed at Restek to service these requests and develop new, innovative coating technologies using the CVD process.

  • 2000: Siltek® technology is invented specifically for GC inlet liners. The Siltek® technology marks a significant upgrade to Silcosteel® with more robust inertness to a variety of chemical compounds, enabling greater analytical sensitivity.

  • 2001: Sulfinert® is released, reflecting the application of Siltek® technology on a wider variety of sample flow path components beyond inlet liners, including sample cylinders, valves, fittings, transfer tubing, and more. Sulfinert® is written into numerous customer methods and environmental standards to ensure reliable chromatograph performance.

  • 2002-2008: Restek Performance Coatings division develops several new coatings based on the original Silcosteel® silicon CVD coating technology to solve material challenges in a range of industries and applications well beyond chromatography.

  • 2009: Restek becomes 100% employee owned and SilcoTek is spun off as an independent company. SilcoTek, now a vendor to Restek, rebrands its coating technologies to solidify this evolution into its own company. Sulfinert®, the flagship inert coating, is renamed SilcoNert® 2000. 


Founding-GroupSilcoTek’s founding members who left Restek to pursue a new vision for Game-Changing Coatings.

The differences between SilcoNert, Silcosteel, Siltek, and Sulfinert

These coatings are much more similar than they are different. In fact, some of them aren’t different at all. The main differences simply come down to nomenclature. Leave it to marketing people to cause confusion (full disclosure: I am a marketing person)!

This comparison chart covers everything you need to know about the differences between these coatings. The differences are called out with italicized red text:


SilcoNert-Comparison-Chart 08032022


Selecting the Best Coating

You will see SilcoTek use the SilcoNert® brand names while Restek uses the traditional brand names of Silcosteel® and Sulfinert® for their products that are coated by SilcoTek. These trademarks for the coating names are all owned by SilcoTek, and both coating processes are performed by SilcoTek at our state-of-the-art facility in Bellefonte, PA.

SilcoNert® 2000 is almost always the best coating option for improving analytical results in any gas chromatography application. In rare cases where a hydrocarbon surface is problematic, SilcoNert® 1000 or Silcolloy® (several layers of SilcoNert® 1000 applied as one coating) will provide a pure amorphous silicon coating to shield your sample media from flow path surfaces.

How to Order

SilcoTek only provides coating services and does not manufacture or sell any products, so we rely on great partners like Restek to streamline the process of getting coated parts. If you have custom chromatography components or products for different applications that you would like to get coated, please request a coating quote on SilcoTek’s website.

If you need inert-coated chromatography products like sample cylinders, valves, fittings, inlet liners, or tubing, visit Restek’s website or check out our other approved customer partners who can work with you directly and ship already-coated products off the shelf.

What about pricing?

SilcoTek charges the same price for SilcoNert® 1000 and SilcoNert® 2000. Pricing is based on several factors, including but not limited to the size and complexity of the part(s) being coated. For pricing from other vendors, please contact them directly. Click here for more details about buying and using SilcoTek’s coatings.


It may seem like choosing the best inert coating for your gas chromatography application is complicated, but hopefully this blog article has made it simpler for you. SilcoNert®, Silcosteel®, Siltek®, and Sulfinert® are all different brand names for a coating technology that first revolutionized the chromatography industry more than 30 years ago. Whether you choose to get your products custom-coated by SilcoTek or work with one of our approved partners like Restek to purchase already-coated products, you know you are getting innovative products you can trust.

Do you work with HPLC or applications that are totally unrelated to chromatography? Fear not! SilcoTek has a wide range of Game-Changing CoatingsTM for you to choose from to maximize the performance and extend the lifetime of your products and processes. Contact our technical service team to begin discussing which option is best for you: 

Need Help Selecting a Coating? Contact Our Technical Service Team