metal:according to Standard NF 9001-CE 0197-EN IOS 9693

and IOS is International Standards Organization, so be careful.

metal = metal, it is the alloy used for the bridge.

norme = standard. If you think it is unclear you may add "complies with" or "according to", but I do not think it is more necessary in English than in French.

NF = the french initials of Norme Française. It is the local label delivered by The French AFNOR (Association Française de NORmalisation). This cannot be translated and should be left so. Unless you want to remove it because it is not important for the target country, or substitute ISO 9001 for NF 9001 because NF 9001 = French version of ISO 9001).

CE stands for Communauté Européenne (European Community) and is therefore EC in English.

EN stands for European Norm (although Norm should be translated by Standard it has been accepted to leave it so for convenience.

IOS stands for International Organisation for Standards and should be translated by ISO (International Standards Organisation), It sounds somewhat ridiculous but it is so !

Just a supplementary - I would think that IOS is a typo and should be ISO