The Gun Metal finish is obtained by treating steel with a physical process called PVD (Phisical Vacuum Deposition) which deposits particles of noble metals on the surface. The result is a unique and refined aesthetic effect, and an improvement of the mechanical properties of the steel which is more... with a physical process called PVD (Phisical Vacuum Deposition) which deposits particles of noble metals on the surface. The result is a unique and refined aesthetic effect, and an improvement of the mechanical properties of the steel which is more resistant to impact and scratches.