Bill is right. The Japanese have this reverence for all things sharp; be it knives, swords or saws. The best factory knife I own is a gentelman's folder made in Seki, Japan. It's in ATS-34 and holds an edge forever it seems.
I don't know what these Winchesters are made of, but in the past I know they were among the cheapest of Chinese manufacture. The blades are/were typically 420 steel, which is bottom line for stainless. You'll know more when you use them. For all I know, for this model Winchester might have contracted with someone else.