Engineers continually face two issues that affect equipment components and can cause major problems in operation and safety: galling and wear. What can be done?

Enter Stainless Steel

Stainless steel provides excellent corrosion resistance and withstands high temperatures — two characteristics that make it an ideal material for components that must withstand movement and high levels of friction. It better resists corrosion than aluminum and other steels, and it is less expensive than titanium and cobalt alloys.

The four types of stainless — austenitic, ferritic, martensitic, and precipitation hardening — vary in their respective levels of corrosion resistance, with austenitic providing the greatest resistance. Each type serves its own purpose in various applications. Martensitic, for example, is an excellent choice for surgical instruments because of its hardness, whereas ferritic is not because it cannot be hardened by heat treatment and can only be moderately hardened by cold working.

What Exactly is Stainless Steel?

Adding at least 12% chromium to steel classifies it as stainless. That’s because the chromium, when combined with the oxygen in the atmosphere, forms an invisible oxide layer. When scratched, the oxide layer naturally reforms. As a result, the steel resists rust and abrasions and, by extension, reduces the chance of contamination. This last attribute makes stainless steel well-suited for the culinary and medical industries; the former attributes allow for its use in bearings, aircraft landing gear, and other high-friction applications.

NiCoTef® Reinforces Stainless

Even stainless steel can experience wear and galling due to factors like friction and surface hardness. These conditions lead to surface degradation that can produce particles that in turn can contaminate their environment. In the medical and food industries this is unacceptable.

That’s where Nimet Industries comes in. Nimet’s engineers work with engineers in the medical, pharmaceutical, and aerospace industries, among others, to identify performance needs in bare-contact materials and to develop solutions. Precision metal finishes like NiCoTef® that use Teflon® function as a dry lubricant and increase surface hardness, ultimately increasing wear resistance. NiCoTef® has been approved by the FDA in countless applications. More information about NiCoTef® is available on our website.

Case in Point

Engineers from a major manufacturer of laser lithography equipment used in the production of semiconductors contacted Nimet about a problem they were having with galling. Most of their machine components are made from stainless steel and are assembled robotically in a clean room environment. The threaded stainless fasteners were galling during installation, causing some to break and others to overload the robot because of friction, which caused the line to shut down. Because of sanitation requirements, the engineers had to find a surface treatment that would reduce friction without contaminating the environment; liquid and dry lubricants were out of the question.

Nimet had the solution that met all the requirements: NiCoTef®.

NiCoTef® has reduced the manufacturer’s costs in a number of areas. Since implementing NiCoTef® treatment, the manufacturer has eliminated all of their assembly line issues and now uses NiCoTef® on all of their fasteners. The cost to coat with NiCoTef® is a fraction of what the downtime had cost, and NiCoTef’s corrosion protection enabled the manufacturer to convert many of the fasteners from stainless steel to less expensive steel alloys.

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