I am very skeptical about this whole thing in the first place so take this with the proverbial 'grain of salt'.... The are many grades of stainless steel and the all qualify to be called 'stainless' and the ones that they use for 'ordinance' steel are just that 'ordinance', but depending on the ingrediants used in the stainless formula it can and does have a different outward appearance.

Could it be the steel they are using is or does not have the luster that we commonly associate with 'stainless' - so to cover this they coat it.

Also I want you notice I am not trying to refer to a lesser quality stainless. But everyone wants to reduce the cost of manufacturing to increase the bottom line. True 4140 is not cheap!