The misunderstanding on my part was intronduced by the facts that 154cm isn´t really common here and we use upper case letters for steel designations.
I saw a documentary about the Hubble telescope. AFAIR they said that a flaw was introduced because a tiny flake of paint was missing and the shiny metal fouled up the measuring. However differences in units and reference systems can and do cause problems. Doing conversions the wrong way is not going to be a highlight in one´s CV.