Galvanizing, electroplating, anodizing or paint... Whatever the coating, one of the first things the customer asks about is thickness. If the coating is too thin, protection falls short; if it is too thick, cracking, flaking or dimensional problems appear.
Common measurement methods
- Magnetic method: For non-magnetic coatings on steel (galvanizing, paint). The most widely used method on the shop floor.
- Eddy current: For insulating coatings on non-magnetic metals such as aluminium (anodizing, paint).
- Microscopic cross-section measurement: Done by taking a section from the part; the most reliable but destructive method. Used when there is a dispute.
- Coulometric and X-ray methods: Used in the laboratory for thin metallic coatings.
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Which of these is in your records?
Knowing the list is easy. The real question is which one is missing from your own records. These gaps slip past when files are read by eye, and auditors look for them first. Upload your thickness measurements to NTB SpecPro and quickly see which points may carry risk, the likely reason and a suggestion.
More than thickness
Even when the thickness is acceptable, blistering, runs, roughness, colour differences and adhesion problems can get a coating rejected. Visual inspection and adhesion testing are also part of the check.
The NTB SpecPro coating module evaluates your measurements against the relevant standard, marks surface defects with the camera and prepares a PDF report. Final evaluation stays with your authorized quality personnel.
Prepared by NTB SpecPro process quality engineering; reviewed by an engineer holding the International Welding Engineer (IWE) qualification. Questions: info@ntbspecpro.com
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