Knives is sharp. Knives kin cutcha. Knives is daynjrus.
OK, here's the Readers Digest version.
Cutlery metallurgy is complex.
* Yes, many stainless steel knives are harder to sharpen and do not hold as fine an edge as carbon steel. But not all.
* Yes, many carbon steel knives are easier to sharpen and hold an edge longer than stainless steel blades. But not all.
* Many stainless steels are more expensive than carbon steels. But not all.
Metallurgy is much more complex than O1 and 440C. Most economy knives are made using whatever is easiest to machine or heat treat. Many are made using cast blade blanks.
A top of the line knife will be made from metal with a very fine crystal structure, typically a spring steel, die steel, tool steel, or aerospace alloys, depending on the characteristics the maker is trying to achieve. The older spring steels (10 series like 1060 and 1095), oil hardening steels (O1, O2, etc), and air hardening tool steels (A1, A2, etc) work well for knife-making, are reasonably priced, and hold an edge very well. And since they are easy to heat treat, you can harden them in your shop.
Common tool steels will be A, W, O series, T or M series, or AUS series. In general, they are tough and hold an edge well, but some are just tough.
Common die steels used for cutlery are D2 and S7. They are tough and hold an edge well, but since they are wear resistant, they can be hard to sharpen. They also need more complex heat treating, involving at least a heat treating oven.
Martensitic stainless steel (stainless containing iron) consists of more than 440C, there are numerous alloys used for blades. In general, 440C is easy to machine and does not hold an edge at all well, but there are exceptions depending on who makes it and how it is heat treated. Other stainless steels like 154CM do hold an edge well.
Custom knife makers use exotic alloys that display the characteristics they want, but they can charge more so they can use higher cost metal.
Heat treating is complex and expensive, and steels that require special treatment will cost more to turn into a blade.
Some of the newer steels being used for knifemaking are more complex, actually incorporating tungsten carbide or titanium nitrite into the steel during the production process. These are sold under several trade names. With these steels, while the edge does not seem especially sharp, it will cut for a long time.
There is a lot of information on the internet, but you have to wade through the BS to get to it.
That's what I know!!
