PVD coatings explained

At a glance

1 micrometre (µm) is a thousandth of a millimetre. Figures are as published by the sources named, not a guarantee from any coating house.

What PVD is, and what this sheet adds

Our journal article on PVD steel finishes explains the process, the colours and where it is used. This sheet adds what it leaves out: published thickness and hardness figures, the limits with their sources, the standards that exist, and wording to specify and approve it.

PVD stands for physical vapour deposition. Euro Inox describes it as a family of methods in which a coating material is vaporised and deposited as a thin film on a surface, in a vacuum chamber. The layers it makes are ceramic rather than metallic. The coating house datasheet we read lists materials such as titanium nitride, zirconium nitride and diamond-like carbon.

Thickness and hardness

One coating house publishes a thickness of 0.2 to 2.0 micrometres for its decorative coatings, and a hardness of 1,500 to 2,800 HV (measured as HV 0.05) with a coating temperature of 20 to 200 °C. Euro Inox, in a general guide to coloured stainless steel, gives about 0.3 micrometres as typical. The two are consistent.

These are very small numbers. A coating of 2.0 micrometres is 0.002 mm, and one of 0.3 micrometres is 0.0003 mm. That is similar in size to the roughness of a brushed finish, so the coating cannot fill or hide the texture beneath it. Euro Inox says exactly that: because the coating is so thin, the texture of the underlying finish is visible. It follows that the polishing, and the finish code beneath, are what the eye reads. See the factsheet on stainless steel finish codes in this library.

We do not give a minimum thickness to specify. A thickness figure is only meaningful if the coating house certifies it and says how it was measured, so ask for that rather than quoting a number from a brochure.

What PVD can and cannot do

• It is hard and scratch resistant, not scratch proof. Euro Inox says PVD coatings produce hard, scratch-resistant surfaces and are much more scratch resistant than electrochemical colouring, but that the colour can be damaged if it is attacked aggressively, and that this damage is not repairable.
• It cannot be repaired on site. Euro Inox gives panel replacement as the repair for coloured stainless steel. Ask the coating house whether a part can be stripped and recoated, and what that does to dimensions and colour.
• The base finish shows. Fabricate, weld and polish to the final finish before coating. Welding must be done before the coating is applied.
• Forming after coating is risky. If stainless steel is to be bent or formed after coating, Euro Inox advises making product acceptance subject to a bend test, because a poorly processed coating can delaminate when bent or knocked.
• The part must fit the chamber, and must be reachable. Chambers have limits on size: one house lists 1,500 mm long by 900 mm across, and your coating house will have its own. The vapour travels in straight lines, so deep recesses can coat unevenly.
• Not every metal goes in directly. The datasheet we read lists stainless steel and titanium directly; aluminium, brass, zinc die-cast and ABS need a nickel and chrome plating first.

What to specify

• The substrate and its grade, and the base finish by its EN 10088-2 code with a measured roughness, approved before coating.
• The colour, by an approved physical sample, not by a name. Ask what colour tolerance the coating house works to.
• The thickness, as the minimum the coating house will certify, with its measurement method and a certificate for the batch.
• The tests and acceptance criteria, agreed before manufacture. BS ISO 23100:2024 exists for decorative PVD on kitchen and sanitary ware fittings; it names performance and test methods for that product. For architectural metalwork there is no equivalent we have found, so agree adhesion, abrasion, colour and corrosion tests with the coating house. Salt-spray testing is done to ISO 9227, but the standard does not set the hours for any product, so the duration must be written in.
• Batches. Coat every part of one visible run in the same batch where possible, so colour matches.
• Protection. Euro Inox notes that strippable plastic film is commonly used to protect coloured surfaces in transit and on site, and that its recommended maximum life must not be exceeded before it is removed.
• Where the part is held. Agree with the coating house where it is held in the chamber, so the contact point falls on a hidden face.

Care and cleaning

This is general guidance from Euro Inox for coloured stainless steel, which includes PVD. Take the coating house's own care sheet for the specific coating and put it in the operation and maintenance manual.

• Clean with mild detergent in water, using a soft cloth or a soft-bristle plastic brush.
• Do not use metallic brushes, abrasive compounds or scouring pads. Avoid high-pressure water jets.
• Wash off mortar and cement splashes straight away, because alkalinity can discolour coloured finishes.
• Leave graffiti and heavy remedial cleaning to a specialist cleaning company, with advice from the finish supplier.

Component: stainless steel, grade [1.4301 (304)], base finish [2J] to EN 10088-2 (edition [to be confirmed]), grain [vertical], approved before coating. All welding and polishing completed before coating. Coating: PVD, colour [name / reference], matched to approved reference sample [ref. __] within [tolerance agreed with the coating house]. Thickness: not less than [__] micrometres, as certified by the coating house with the measurement method and a certificate for each batch. All components of one visible run coated in the same batch where possible. Contact points from the rack to fall on [hidden faces]. Parts protected in transit with [strippable film], removed within its recommended life.

Coating performance to be demonstrated on [a production-representative sample] before manufacture by tests agreed with the coating house: [adhesion or bend test], [abrasion test], [corrosion test to ISO 9227 (edition [to be confirmed]), duration [__] hours], [colour measurement against the approved sample]. [For kitchen or sanitary fittings, BS ISO 23100:2024 may be referenced (edition [to be confirmed]).] Test reports to be supplied for [the first batch / each batch].

Clean with warm water and mild detergent using a soft cloth or soft plastic brush, then rinse and dry. Do not use abrasive cleaners, metal brushes, scouring pads or high-pressure jets. Remove mortar or cement splashes immediately. Damage cannot be repaired on site: report it to [contact], and replace or recoat the part through [the coating house]. Follow the coating house's care sheet [ref. __].

Standards and sources

• Euro Inox, Colouring Stainless Steel (Materials and Applications Series, Vol. 16, 2011): PVD section and cleaning chapter; BSSA-hosted.
• A coating manufacturer's decorative-coatings datasheet: thickness, hardness, temperature, substrates, chamber size; read 5 November 2026 (source named in the review notes).
• BS ISO 23100:2024: Decorative PVD coatings on kitchen and sanitary ware fittings, specification and test methods (BSI, 31 December 2024). Text not read.
• ISO 9227:2022: Corrosion tests in artificial atmospheres, salt spray tests. Text not read; it does not set hours for any product.
• BS EN 10088-2:2024: Stainless steels, for the base finish codes; see the finish codes factsheet.
• Make Bespoke Studio journal: PVD steel finishes: process, colour and use.

Questions we are asked

How thick is a PVD coating?

One coating house publishes 0.2 to 2.0 micrometres for its decorative coatings, which is 0.0002 to 0.002 mm. Euro Inox gives about 0.3 micrometres as typical. Ask your coating house for the certified minimum and how it is measured.

Can PVD be repaired if it is scratched?

Not on site. Euro Inox says damage from aggressive attack is not repairable and that repair of coloured stainless steel is by panel replacement. Ask the coating house whether the part can be stripped and recoated.

Does PVD hide the finish underneath?

No. The coating is so thin that the texture of the base finish shows through, so polishing lines and weld marks remain visible. Finish the metal fully before it is coated.

Which metals can be PVD coated?

On the datasheet we read, stainless steel and titanium directly. Aluminium, brass, zinc die-cast and ABS need a nickel and chrome plating first. Confirm with the coating house what it handles.

How do I clean PVD coated metal?

Use mild detergent in water with a soft cloth or soft plastic brush, then rinse and dry. Avoid metal brushes, abrasives and high-pressure jets, and follow the coating house's care sheet.