The wonders of stainless steel

It’s strong, it doesn’t rust and it’s shiny. It’s non-magnetic, it’s inexpensive, it’s heat resistant and it’s shiny. It’s easy to fabricate, easy to shape, easy to weld, easy to clean, inexpensive and it’s shiny! If each of these attributes was totally accurate everything in the world would be made out of stainless steel!
The term ‘stainless steel’ has become a generic which today covers a wide range of iron alloys that contain at least 10% chromiumand 50% iron. But originally it was the invention of the cutlery industry - a material that didn’t need cleaning like silver and didn’t rust like mild steel. A material that was inexpensive, relatively easy to work, was tough and actively resisted corrosion. Once the principle had been establisheddifferentv steels were deeveloped for different purposes and environments.

The marine application of the stainless steel principle, because the operating environment is so hostile has involved the addition of nickel and molybdenum. The end result was the creation of a salt proof alloy known today as Marine Grade 316 which is tough, corrosionfree and non-magnetic. (so if you put a magnet onto a stainless steel itemand it sticke then be warned, it's not the right stuff).

Grade 304 - 18% chromium + 8% nickel is most commonly produced(austenic chromium nickel) steel in the world accounting for over half of the global production. It is useful for exposed components frequently washed by fresh water. However the complete lack of molybdenum makes it prone to crevice corrosion and pitting. It can also form rust streaks from drilled holes.

Grade 316 - austenic stainless with 2% - 3% molybdenum