I think what people mean when they say "reinforced with metal" is "reinforced with substances in metallic form". From that point of charity we can start to say

I think what people mean when they say "reinforced with metal" is "reinforced with substances in metallic form". From that point of charity we can start to say things like "Organic environments cause corrosion in commonly-available pure metals", or "Pure metals can be toxic to animal cells in large amounts".