PEN-TUF®/EN – What is it and why choose it for your application?


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Electroless Nickel Plating with PTFE (PEN-TUF®/EN) is an advanced metal treatment, or coating, that offers dry lubrication, high lubricity, and excellent wear and corrosion resistance. The process was initially developed over 20 years ago by Advanced Surface Technologies and can be applied in two ways – co-deposited or infused.

Co-deposited (which is the standard used by UC Components, Inc., infused available by request)

Co-deposited PEN-TUF®/EN involves evenly dispersing PTFE (polytetrafluoroethylene) particles suspended into an electroless nickel layer when plating a part or assembly.


Infused PEN-TUF®/EN involves spraying PTFE onto a mid-phosphorous electroless nickel plating and then baking it onto the part or assembly. This application gives the surface exceptional mold release properties and corrosion resistance.

PEN-TUF®/EN combines the low friction release properties of PTFE with the resistances and hardness of electroless nickel, which makes it an ideal treatment for clean-critical components and assemblies that cannot use conventional lubricants or release sprays.

Industries such as:
-Aerospace & Space
-And more
Applications such as:
-Non-galling threaded parts
-Stamped washers
-Injection molds
-And more

PEN-TUF®/EN coating can be applied to various metals, including aluminum, brass, copper, stainless steel, and many more. The process is similar to electroless nickel plating, meaning that the coating is applied via an autocatalytic chemical reaction making it an incredibly uniform, reliable, and repeatable coating process. It can effectively coat parts that have complex geometries, sharp edges, deep recesses, seams, threads, and more. A part or assembly coated with PEN-TUF®/EN can withstand temperatures up to 500°F, and it is also a more environmentally friendly alternative to cadmium plating. PEN-TUF®/EN meets AMS2454 2012-04 specifications and is also both End-of-Life Vehicle regulations (ELV) and Restriction of Hazardous Substances (RoHS) compliant.

Why choose PEN-TUF®/EN?

  • Extreme self-lubrication
  • Dry lubrication
  • Repels water, oil, and other contaminants
  • Superior wear resistance
  • Excellent corrosion resistance
  • Low coefficient of friction
  • Enhanced non-stick surface
  • Uniformly coats even complex geometries
  • Low reflectivity
  • Typically mimics the finish of the base metal
CompositionNickel: 84-85% (by weight)
Phosphorus: 9-11% (by weight)
PTFE: 8-9% (by weight) / 23-25% (by volume)
PTFE Particles: 0.3-0.4 µ-meter diameter
Phosphorus: 7-9% (by weight)
Typical Coating Thickness0.0001”-0.0004” 
Hardness32-35 RC (as plated) 42-46 RC (heat-treated at 300°C / 4 hours)54-58 RC
Coefficient of Friction0.07-0.10 wet 0.1-0.2 dry 
Corrosion Resistance 0.0003” (100 hours salt spray)
Abrasion ResistanceCS-10 wheel/1000g load Weight loss = 20mg/1000 cycles 
Electrical Resistance0.06 Ω per square inch 0.00084” thickness 

PEN-TUF®/EN coating is fully vacuum-compatible and is typically used as a replacement for silver plating in applications where two or more metals may not be compatible. For example, if your assembly is made of aluminum, a silver-plated screw would gall upon installation, while a screw coated with PEN-TUF®/EN would not.

How can UC Components, Inc. help you?

UC Components, Inc. has been the world leader in high vacuum hardware since 1974. We offer a range of finishes for our RediVac® line of fasteners, washers, and hex nuts. These coatings and platings are designed to prevent galling and/or improve the corrosion resistance of the treated component. All our coatings and platings are vacuum compatible, dependent on your specific process chemistry. The right coating or plating for your HV or UHV application is best defined by your process engineer.

View our parts catalog online to find the components you need, request a quote, or contact us for more assistance or additional information. If you do not see the items that you need listed in our standard products, please give us a call! We may not stock it, but we are happy to acquire and manufacture just about any fastener or O-ring you need.

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