The Science Of Precision Coatings


What does TDC stand for?

TDC is an acronym for Thin Dense Chrome, invented by the Armoloy Corporation, Dekalb IL.


What is Thin Dense Chrome (TDC)?

Armoloy TDC® (Thin Dense Chromium) is a pure metallic chromium metal, low-temperature, multistep surface finishing process. Precise deposits ensure fidelity to part contours and details, without the edge build or “dog-boning” associated with conventional chrome-plating methods. The micronodular surface provides a low energy surface that significantly reduces if not eliminates galling, seizing, metal pickups, sticking, and erosion.


Does Armoloy TDC® lower internal stress on the part?

Yes, the high hardness of the coating provides a protective layer reducing stress to the base metal.


What is the bond strength of Armoloy TDC®?

Bond strength exceeds 125,000 psi and will pass severe bend tests.


What is the corrosion resistance equal to?

440-grade stainless steel. As you may know, stainless steel has a higher corrosion resistance properties due to the elevated levels of metallic chromium in the metal itself. Armoloy TDC® is 99.9% pure metallic chrome and offers 100% coverage.


Can the coating be removed permanently or reapplied after removal without damaging my part?

Yes, the coating can easily be removed or reapplied as needed without adversely affecting the part.


What are the benefits of TDC® vs. Hard Chrome?

Thin dense chrome plating offers higher wear resistance, lower coefficient of friction, increased lubricity/release that characterizes industrial hard chrome but because it is not a micro-cracked deposit TDC®/XADC® provides a superior level of corrosion protection. The lower deposit thickness minimizes dimensional change and yields less problematic buildup at sharp edges and maintains balanced geometries. 


Do parts require post-machining or grinding after plating?

Often, no. Armoloy can plate accurately within .000050 (1.2 Microns)


Is Armoloy TDC® different from Flash Chrome or generic TDC?

Yes. Often we are flattered to hear that other plating providers advertise or offer a TDC® product in efforts to compete with our process. Armoloy invented both the chemistry and process over 60 years ago, and has yet to be paralleled in performance. Unlike most coating providers, the Armoloy coating process is engineered for every part and application. The proprietary chemistry and tooling methods used to guarantee best results relating to absolute adhesion and precise coverage can only found at a dedicated Armoloy facility. All Chem Processing is provided and controlled by the Armoloy Corporation’s laboratory to ensure consistency.  


What is XADC®?

XADC® is Armoloy TDC® with a co-deposit of nanodiamonds and modified TDC chemistry to ensure nanodiamond particulates are impregnated into the surface coating.


What is BiProtec®?

BIPROTEC® is Armoloy TDC® or XADC® with a thin layer of Mid Phos nickel applied directly to the base metal before TDC®/XADC® plating process for extreme corrosion protection.


Does Armoloy have a prototype program?

Yes, the Armoloy Corporation has a dedicated team of application engineers and chemists that will work with you to find the best coating and coverage solution.

Is Armoloy the same as Hard Chrome plating?

No, the Armoloy and XADC® coatings are a refinement of the Hard Chrome process. The Armoloy coatings are applied evenly and at much thinner deposits than hard chrome. No secondary machining steps are necessary. The Armoloy coatings also produce a harder surface without micro stress cracking found in traditional hard chrome.


How thick is the coating applied?

Our standard deposit is .0001” to .0003” which is suitable for most applications.  However, the coating can be applied effectively from .00005” to .0007” depending on the application. Deposits of more than .0007” can be achieved, however, micro cracking can occur at these thicker deposits.


How long will my part last after coating?

Armoloy can extend the functional life of parts anywhere from 2x to 10x longer depending on the application and environment.   Once the coating has worn, parts can be returned for stripping and re-plating instead of purchasing new components.


I think the Armoloy coating has worn off is there way I can check that?

You can apply a drop of Copper Sulphate onto the area in question and if it turns Blue the coating is still intact but if it turns Orange then the coating has finally worn off.  It’s very important that you clean the area tested with a strong cleaning agent such as Acetone as the copper sulphate can damage the base metal if left on.  This test cannot be done on Stainless Steel.


What is your turnaround?

3 to 5 days turnaround is typical for most parts.  Large components or high part volumes will need to be reviewed prior to committing to a delivery date.  Same or next day service is also available upon request.


Do I need to disassemble my parts before shipping to you?

Yes, please completely disassemble any components so that we may properly apply the coating onto each part independently.


How large of a part can you plate at Armoloy of Illinois?

We can plate parts up to 34’ in length and have the capacity to lift parts weighing up to 10,000lbs.


What kind of temperatures will my part be exposed to?  Is there a possibility the base metal could be negatively affected?

The Armoloy process is considered a “cold” process with maximum temperatures of 170°F.  Unlike some high temperature coating processes, our process will not distort the base metal or negatively affect heat treatment properties.


Is Armoloy RoHS Complaint?

Yes, and we can send documentation stating this from the Armoloy Corporate Laboratory as the finished product is pure metallic chromium metal.


What specifications can the Armoloy coating be certified to?

AMS 2438 and QQ-C-320 are the most common specifications we encounter, however, we can certify to most any specification involving this dense chrome.


 Can Armoloy be used in the food/medical industry?

The absolute bond of the Armoloy coating and anti-galling properties of the Armoloy coating make it ideal for these industries. The coatings are USDA approved and FDA compliant.


Is Armoloy chemical resistant?

In most cases yes.  Please provide the name of the chemical, concentration and conditions in which it is exposed so we can give you a definitive answer.


Will caustics wash downs affect the Armoloy coating?

The crack free surface of the Armoloy coating will provide corrosion resistance for food/medical wash downs with the proper clean water rinse afterwards.


Can my parts be machined or welded/brazed after they are coated?

Yes, both operations can be performed after the coating is applied.  During machining, tool life may be negatively affected due to the high hardness of the coating.  There are no adverse side affects from welding or brazing after coating.  Alternatively, parts that require machining can be shipped back to Armoloy to be stripped prior to machining.


How does Armoloy effect the surface finish of my parts?

The coating itself has no inherent RMS reading of its own, Armoloy mirrors the surface finish of the base metal.  The Armoloy process will negatively affect surface finishes less than 8 RMS due to the preprocessing of the base metal.


Can the coating be polished for an improved finish?

The Armoloy coatings can be post polished, but due to the nodularity of the coating cannot deliver a mirror finish appearance.


Do you offer Polishing Services, Electro Polishing or Passivation?

Yes, we can assist you with those additional services, we are your one stop shop for any pre or post plating needs.


Can Armoloy be run against itself?

Armoloy is one of the few coating that can be run against itself, making it ideal for low or no lube applications. Remember to account for coating deposits when determining tolerances.


Can parts be stripped and re-coated?  Will this negatively affect the base metal?

Parts can be stripped and recoated many times over, saving you the cost of manufacturing new components.  The removal process is a benign process that will not affect your base material. Parts can be stripped and re-coated on a preventive maintenance basis if required without affecting size or base material.


Can someone come to our company and observe the problems we are dealing with?

In many cases yes, although this depends on the proximity to an Armoloy locations and the size of the issue.


Can you send me sample for testing?

Yes. However, it would be better if you were to send us a coupon of the substrate you are interested in testing.  Please contact us to discuss your project, we may already have the answer you’re looking for.




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Machined Components

From fundamental components such as shafts, gears, and bearings, to the more complex components found in automated lines, packaging machines, and specialized machinery of every type, Armoloy of Texas can... Read More

Automation + Linear Motion

For over 20 years, Armoloy TDC has been the premier coating for the Linear Motion industry. The Armoloy TDC coating lowers the coefficient of friction of bearing steels, for smoother movement over rolling surfaces... Read More

Pumps And Compressors

For protection against the most common forms of wear including corrosive, abrasive, and erosive wear, consider coating your critical pump, valve and compressor surfaces with a protective Armoloy coating... Read More

Food Processing And Packaging

Apply Armoloy TDC® and BoronG (Nickel Boron Nitride) to food-processing and food-packaging equipment and components for the most beneficial combination of wear resistance and corrosion resistance... Read More

Oil And Gas Extraction

In the field of oil and gas drilling and extraction, the Armoloy coatings are ideally suited for components operating in corrosive downhole environments. The coatings’ high corrosion and wear resistance... Read More


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