Have you ever wondered, "What is Salsbury Steak?" I've got a chart that shows where each cut of beef comes from, where T-Bone steaks come from on the cow, what part the rib roast is, etc. But I can't find the Salsbury on it. The anwer is that Salsbury Steak is bits and pieces of leftover meat all ground up together and pressed into a sort of patty shape. It's cheap because those bits and scraps would have been thrown away otherwise. Of course, the quality of it is generally not so good and sometimes quite poor.
Generally speaking, "Surgical stainless steel" is whatever stainless steel they have extra of. Very often, it's the scraps of many different types of stainless steel left over from making things that need to be a specific alloy all put into one big pot and melted down together. If you want to order it, you'd ask your supplier for "stainless pot steel." "Pot steel" is a non-specific mixture of steel scraps and bits melted together. It's a classic pre-consumer recycled material. It's a popular material because it's cheap. It's used for a lot of applications where you need steel, but don't need the special characteristics of a specific alloy. If you're a bit careful about what you throw into the pot and only take stainless alloys, you get a slightly better grade product, "stainless pot steel."
Stainless pot steel, a.k.a. surgical stainless steel, is good for applications that need a stainless steel but don't need the exact traits of a specific specialty alloy. A good example of that is many surgical impliments.
Surgical Stainless Steel is the Salsbury steak of the steel industry.
Neither pot steel nor stainless pot steel are good for knife blades.
One reason knife manufacturers like to use generic terms like "stainless steel" or "surgical steel" is that it frees them from having to use a specific alloy. If your tooling is all set up to stamp "440C" on the blades and your boxes are all printed with "440C" and you've run a big ad campaign, printed catalogs, etc. listing 440C, then you're locked in. If the price of 440C rises unexpectedly, you just have to eat it. And if your steel supplier calls up and says, "We've got a special today on 420HC," you can't take advantage of it. You've got to have 440C. But, if you just stamp your blades "Surgical Steel" and promote that in all your ads etc., then you can use whatever steel is cheap and available and you're free to change alloys from production run to production run as the steel market changes.
