According to their website the Frontier pads are a proprietary alloy of stainless steel, nickel silver, monel (a corrosion resistant nickel based alloy), and zinc that is harder than rust but softer than bluing. I just received an order for a dozen pads and they do seem different than a straight stainless steel pad. Probably not worth removing bluing or scratching the metal just to save a couple of bucks.
https://www.big45metalcleaner.com/