Just because a steel alloy is marketed as being “food grade” doesn’t mean it’s the right material for your production process.
There are a number of different stainless steel alloys on the market, each with its own strengths and weaknesses when it comes to resisting specific chemicals and production environments.
For example, salt is known for being exceptionally corrosive to metal compounds. While grade 304 stainless steel is resistant to most corrosives, prolonged exposure to salt can still eat away at it. So, grade 304 stainless wouldn’t be suitable for any process requiring repeated, prolonged exposure to salt or saltwater.
Grade 316 stainless, on the other hand, is much more resistant to salt exposure than grade 304. This makes grade 316 stainless steel preferable for food makers that use salt or saltwater in their products