Stainless steel is a steel than contains at least 10% chromium. But there are many nuance of stainless steel, with different composition for various applications, and some do contain nickel. But not all types of stainless steel contain nickel.
Yes. Different alloys contain differing amounts.
*Most of the grades of stainless steel contains nickle except few grades of ferritic/Martensitic stainless steel. For example , SAE416 / SAE 420 does not contain Nickle. See Stainless steel designations table at following link:
Steel okorder /... So take a magnet to the steel in question: if the magnet sticks, the steel is unlikely to contain nickel.
