Fistula ferri immaculata ad gas repugnans, aqua vaporosa et alia medium mordax languens significat.Ferrum acidum repugnans refertur ad acidum, alcali, sal, etc.
Typus: I fistula immaculata ferro inconsutilem;II Fistula ferro immaculata iuncta.
Secundum splendorem: tubus chalybeus vulgaris immaculatus, tubus chalybs mattus immaculatus, tubus ferreus inactus lucidus.
Standard：ASTM A213, ASTM A778, ASTM A268.ASTM A 632, ASTM A358
Adhibentur in pipelinis industrialibus et in structuris mechanicis sicut petroleum, chemica, medica, cibus, industria, machinatio mechanica, etc.
