Powder Coated Parts

How powder coating actually works

Powder coating is a coating that sits on top of the metal, not a treatment of the metal itself. A gun gives the dry polymer powder a negative charge and sprays it toward the grounded part, where it clings, and heat then melts the powder into one continuous film (source 1). Common powders cure at about 200 °C (392 °F) object temperature for 10 minutes, and some cure lower, around 160-180 °C (320-356 °F) (source 1). The result is an opaque color coat that hides the substrate underneath.

That’s the key difference from anodize, which is an oxide grown down into the aluminum surface and out from it by equal amounts (source 6) rather than a coat added on top. Type II anodize runs 0.00007 to 0.001 in thick (source 6), against a powder data sheet range that can run 1.5 to 3.0 mils, or 0.0015 to 0.003 in (source 2). If you want a thinner finish, or the aluminum surface to stay visible, compare the two on the anodizing page first.

Durability, color, and texture

Powder coating has long been used on metal objects that see rough use, and it builds a much thicker coat than conventional liquid coatings without running or sagging (source 1). A powder supplier’s data sheet gives the film range for that powder, which can be as broad as 1.5 to 3.0 mils (0.0015 to 0.003 in), and a part headed outdoors may call for 2.5 to 3.5 mils (source 2). It is a common call for brackets, frames and parts that get handled hard.

Color, gloss and texture come from the powder supplier’s range, and the print names the one you want. Texture is more than a look: an orange-peel texture helps hide metal defects and is less prone to showing fingerprints (source 1). A finish called out on the print is quoted with the part. See more finish options across the catalog on the CNC surface finishes overview.

What to mask and where it fits

Because the film builds on every surface it covers, it changes fits, and how much it varies depends on the shape of the part (table below, source 3). In powder coating practice, threaded holes are masked with silicone plugs and flat areas with high-temperature tape (source 4). Mark the threaded holes, bearing bores, sealing and mating faces, and any ground or electrical-contact point that has to stay bare on the print, and the masking is quoted with the part. For a sliding fit, say so in the part description.

The cure heat is the other thing to watch: the part has to tolerate the cure temperature, about 200 °C (392 °F) for common powders (source 1). Pressed-in inserts, plastics or sensitive assemblies may not tolerate it. Tell us what has to survive as-is and what can be masked. Michigan companies ordering powder coated CNC parts as one job can read how that works on the Michigan page.

Materials and pretreatment

Powder coating is mainly used on metal objects (source 1), and it is quoted on steel, stainless and aluminum. On bare steel, a conversion coating such as iron phosphate is commonly added after cleaning to protect from oxidation and enhance bonding, though iron phosphate has modest corrosion resistance if the coating film is broken (source 5). On aluminum 6061 the print can call for powder when you want opaque color instead of the anodized look.

The finish is specified on the print and quoted with the part, and parts come back finished and inspected. Powder coating is quoted with machined parts, not as a finish-only job on a part you already have. Enclosures and housings are a common candidate, since color and toughness both matter on parts people see and touch: see the enclosures and housings page for examples.

Powder vs anodize, the honest version

Use powder when you want a thick, opaque coating in a color you choose: bold colors, rough use, and anything steel. Use anodize on aluminum when you want a thin finish that is part of the surface. Neither is automatically better, they just solve different problems.

Both are specified on the print and quoted with the part rather than guessed at later. If you aren’t sure which one fits, send the part and the use case, and the team will spec it with you.

Sources

All accessed 30 September 2026. Where a figure here differs from your print, the print governs.

1. Wikipedia, "Powder coating": en.wikipedia.org/wiki/Powder_coating (the gun charges the powder negatively and sprays it at the grounded object; common powders cure at 200 °C (392 °F) for 10 minutes, in European and Asian markets 180 °C (356 °F) for 10 minutes has been the standard, shifting toward 160 °C (320 °F); much thicker coatings than liquid without running or sagging; mainly used for coating of metal objects, particularly those subject to rough use; orange-peel texture helps hide metal defects and shows fingerprints less).

2. Rodger Talbert, "Powder Coating Thickness Guidelines," Products Finishing, 1 July 2013: pfonline.com/articles/coating-thickness-guidelines (a powder supplier’s recommended film range may be as broad as 1.5 to 3.0 mils; outdoor or harsh use may need 2.5 to 3.5 mils).

3. Rodger Talbert, "Film Build Control," Products Finishing, 30 January 2014: pfonline.com/articles/film-build-control (film build can be held to ±0.5 mil on flat or simple surfaces, varies ±1 mil on a medium-complexity shape and by as much as 2.5 mils either way on a very complex part).

4. Lee Lechner, Echo Engineering and Production Supplies, "Powder Coating Masking Fundamentals," PCI Magazine, 21 May 2020, pcimag.com/articles/print/107459-powder-coating-masking-fundamentals (masking threaded holes before powder coating is necessary; silicone tapered plugs for blind holes, silicone pull plugs for through holes, high-temperature tape for flat areas).

5. Rodger Talbert, "Powder Coating Q&A: Pretreatment Methods," Products Finishing, January 2016: pfonline.com/articles/powder-coating-qa-pretreatment-methods (once steel is cleaned a conversion coating is desirable to protect from oxidation and enhance bonding; iron phosphate works well with powder but has modest corrosion resistance if the coating is film broken).

6. Wikipedia, "Anodizing": en.wikipedia.org/wiki/Anodizing (sulfuric-acid coatings of moderate thickness, 1.8 μm to 25 μm (0.00007 to 0.001 in); the oxide is grown down into the surface and out from it by equal amounts).