Powder Coating & Painting for Machined Parts

What it is and when to specify it

Powder coating is a dry finishing process in which a thermoset powder is electrostatically applied to a part and then cured in an oven, where it melts and flows into a continuous film. The key difference from liquid paint is the medium: powder carries no solvent, so a single pass can build a thicker, tougher film than most wet paint systems, and overspray can be reclaimed and reused.

The finish is used where parts need a durable, good-looking surface that resists chipping, scratching and everyday handling — enclosures, brackets, covers, housings and consumer-facing components. Colour matching and a wide choice of gloss levels make it a common pick for visible parts. The process is arranged and managed by us through our vetted partner network, managed under one quality process, so one drawing and one document package covers the job. Because the finish is applied dry and cured in one pass, it also builds up well on edges and corners, which are exactly the areas where a liquid paint coat tends to pull thin. For the wider range, see surface finishes.

Specifications

Powder coating thickness is confirmed per drawing rather than assumed. In common trade practice, cured films run in the 60–120 µm range, which is part of what gives the finish its toughness; the exact figure is confirmed per drawing.

Pretreatment matters more than the powder itself. Parts are degreased and given a chemical pretreatment suited to the substrate, so the film bonds and resists lifting or under-film corrosion. Colour and gloss are specified from a colour reference you supply, with gloss, satin, matte and textured finishes available. Masking is a standard part of the job — threads, bores and mating surfaces are masked before coating so they stay free of film.

Parts ship with a material certificate (MTR) and pre-shipment photos. Lead times follow our standard schedule: samples in 5–10 days and production in 25–35 days after sample approval, with the MOQ from 50 pieces and samples from 1 piece.

Which materials and parts it suits

Powder coating suits aluminium and ferrous substrates. We arrange it on aluminium 2024, 5052, 6061 and 7075, stainless steel 303, 304, 316 and 316L, carbon and alloy steel 1045, 1215 and 4140, and brass, bronze and copper. Aluminium parts in particular take powder coating well after the right pretreatment, and the finish is a common alternative to anodizing when the priority is colour and a thick protective film rather than a thin conversion layer.

The finish suits enclosures, housings, brackets, covers and structural components where appearance and durability both matter. It is less suited to high-precision sliding or threaded areas, which is exactly why those features are masked. We also arrange powder coating as a protective topcoat over plated or primed parts where the drawing calls for a layered system. See the full materials list to confirm substrate options.

Corrosion, wear and dimensional impact

A well-bonded powder film provides strong corrosion protection and good resistance to chipping and scratching in service, which is why it is chosen for parts that will be handled or exposed. The film also insulates and seals the surface, giving a clean, even appearance across large areas.

The dimensional impact is the point to plan around. A cured film of 60–120 µm is thick enough to close up threads and change fits, so threaded holes, bores and mating faces must be masked or designed with clearance. We machine precision features to ±0.01 mm and hold ISO 2768-m as a general tolerance, and we confirm the coating allowance against the drawing. Exact thickness is confirmed per drawing. The masking step is why we ask for the drawing early — knowing which holes and faces must stay bare lets us set the coating up correctly before a single part is hung — and every order starts with a quote within 24 hours that includes DFM feedback.