Souvy

The market is more than able to get around such officialdom. The steel industry is a good example of this. As you undoubtedly know, steel plants are big things. They are normally located close to market, close to raw materials or close to an energy source (preferably more than one of those criteria). There are a few exceptions to that rule. Ravenscraig, for example, was a political decision.

Most steelworks in Europe are geared mainly to the local market, with leftovers being exported. For the steelmakers on the continent, this was not an issue because they were all making the same metric sizes. The UK, however, used imperial sizes for the domestic market and metric for exports. It is very costly to re-tool and rolling mill. It was viable for the Brits because they had a large export market to go after. It was not viable for most other producers because they were all competing for a little bit of market.

This was deemed to be a barrier to trade and the Brits were told to go metric. They did. Building codes went metric etc and British Steel started publishing its price lists in mm. The numbers were odd. It didn't take long with a calculator to realise that the products were the same as before but described in mm.