Informing the customers regarding the approximate thickness of the commodity

I wanted to find out a fatwa regarding weights and measures in my business.

We are steel traders. We buy steel a certain thickness say 0.2mm but the factories that produce it can’t get the exact thickness due to the production process. So the thickness varies from 0.195 to 0.205mm, sometimes more sometimes less.

What is the ruling on this because we sell the product as 0.2mm. We sell as per the thickness that we order. We don’t order a lower thickness and sell as a higher thickness. This is purely a production tolerance level as the machines can never get it exact.