The numbers are used to describe the quality and grade of the stainless steel. The two main components used to manufacture cutlery are chromium and nickel.
The numbers 18.10 and 18.0 show the percentage of these components that are present in the stainless steel used:
18.10: 18% chromium / 10% nickel
18.0: 18% chromium / 0% nickel
Whilst chromium gives cutlery its rust-resistant qualities and hardness, it is the job of nickel to enhance its corrosion resistance, as well as providing a silver-like shine.
The higher the nickel content, the more rust resistant and shinier the cutlery will be. This however, does come at a cost as nickel is somewhat expensive.
Looking for cutlery that feels heavy in your hand and has a superior shine and rust resistant qualities? Choose 18.10.
If you will be using your cutlery everyday, dont mind it feeling light in weight and not as shiny, choose 18.0.