PVD steel in watchmaking doesn't refer to a specific type of steel, but rather a stainless steel case or component that's been treated with a Physical Vapor Deposition (PVD) coating.

This PVD process essentially applies a very thin layer, typically between 1 and 3 micrometers, of a different material onto the surface of the steel. Common coating materials include titanium nitride for black, and various metals like gold or rose gold to create different color finishes on the watch.

Here's a breakdown of what PVD coating does for watches:

• Aesthetics: PVD allows for a wider variety of colors and finishes than natural stainless steel, giving watchmakers more design options.

• Protection: The coating acts as a barrier against scratches, corrosion, and wear and tear, keeping the watch looking newer for longer.

• Affordability: PVD gold coating, for example, can provide the look of a solid gold watch at a significantly lower price point.

It's important to note that while PVD is generally durable, some coatings can show wear and tear over time, especially with heavy use.