Considering the end application and location of a staircase will determine what choice of steel the customer makes. Contemporary commercial staircases favour the use of highly polished stainless steel designs for their strong aesthetic appeal. Stainless steel has a high chromium content which gives that ever so obvious sheen, it is also a harder alloy than mild steel which makes it less ductile and somewhat harder to weld.
A visit to any popular consumer retail centre will almost certainly provide example of this type of staircase and or stair platforms. Stainless steel is also very popular in modern business premises, at least within the front of house areas that visitors and clients are likely to see. The landscape and hotel industry also use stainless steel stairs and balustrades to great effect, featuring a mixture of material integrated into the steel framework, such as wood, glass, laser cut panelling and even stone.
There is a greater cost for stainless steel, the price is somewhat dicated by the cost of energy used to make the alloy and secondly the skillset and time elements involved in fabrication. Mild steel is somewhat easier to work with and of course cheaper to manufacture as a raw material. That being said, stainless steel is going to pretty much outlast almost any other material in a modern building and so for that reason alone it makes a good investment choice if aesthetics and minimal to no maintenance costs are factored into the purchasing decision.