19 May Coating Thickness Requirements for Aerospace and Defense Components
Coating thickness requirements are not just values pulled from a specification. They define how much material is actually there to protect the surface and whether that protection is applied consistently.
And for aerospace and defense components, consistency matters even more. Variances can show up in inspection results or assembly fit, or affect performance and durability later on. The solution is finding a certified partner to handle the finishing and test the results.
Why Coating Thickness Requirements Matter in High-Performance Applications
Coatings protect the base material from destructive elements in the environment. They’re meant to be sacrificial, taking on corrosion, friction, and wear before anything else does.
As long as you’re using the right type of finish and that finish is applied evenly, your parts should last longer and resist damage. However, if the coating is uneven or falls outside the recommended range, it does not take long for problems to show up.
Some areas might start to degrade sooner than others. Excessive thickness might create issues with fit or cause stress in the coating itself. But in aerospace and defense, every detail matters. A faulty coating could mean failure at a critical moment.
Minimum Coating Thicknesses for Aerospace Parts
The minimum coating thickness is tied to how the part is expected to perform. Different materials and environments require different levels of protection, so results are expected to stay within a set range. For example:
- Corrosion-resistant coatings such as cadmium or zinc-nickel fall around ~0.0002″ to ~0.0006″, depending on the application.
- Wear-resistant coatings are often used when repeated contact or movement is expected.
- Thermal or specialty coatings can be applied to components that must perform in high-temperature or demanding conditions
- Spec-driven requirements are defined by SAE International, ASTM International, and MIL-SPEC.
Ensuring Consistency in Coating Applications
Consistency depends on how controlled the process is from start to finish. Bath chemistry, current density, plating time, and surface preparation all affect the final thickness. When those factors shift, the results shift along with them.
Calibration
Delivering consistent results means carefully calibrating every aspect of the process, from equipment and chemical baths to surface preparation and timing.
Testing
Destructive testing methods like cross-section microscopy are highly accurate, but the test parts get destroyed in the process. Non-destructive testing methods like x-ray fluorescence (XRF) can test the thickness without causing any damage. And for faster checks during production magnetic and eddy current testing will reveal any inconsistencies.
Compliance
Aerospace and defense work requires traceability, so documentation is very important. Process data and inspection results need to be recorded constantly. This is not just for compliance. It also helps track variations and exposes errors in production.
AS9100 Certified, NADCAP Accredited Metal Finishing in Arizona
Coating thickness directly affects how well high-performance components will perform over time. From setting minimums to checking results and maintaining control over the process, each step plays a role in how well a coating holds up under real conditions.
If you need a metal finishing partner that can meet strict specifications, contact CRC Surface Technologies. We are an AS9100-certified, NADCAP-accredited metal finishing provider. We serve aerospace and defense manufacturers in Arizona and nationwide. To learn more or to request a quote, please send a message to rfq@chemresearchco.com.
Photo by Everson Vansoski on Unsplash used with permission under the Creative Commons license for commercial use 4/29/26.