I often hear a lot of misconceptions about one of my favorite knife steels, 440C stainless steel, and I want to clear up a few of them. 440 stainless steel has gotten kind of a bad rap because a lot of factory knives use 440 stainless, sometimes called "surgical stainless".
It is very important to understand that not all 440 series stainless is the same. In fact, there are different grades of 440 stainless with VERY different properties. There is 440A, 440B, and 440C.
440A and 440B are "softer" grades of 440 stainless steel. While they are VERY rust resistant and will take a great looking mirror polished finish, they will not hold an edge nearly as well as 400C. Factories use the milder steels because the blades are stamped out of sheet of steel using dies. 440C is too hard and expensive for this process. Some manufactures are intentionally vague about the type of steel they use. If the blade is marked "stainless steel", "surgical stainless" of just "440 stainless" you can bet it is 440A or 440B.
440C is a considerably better and more expensive steel and if a blade is made from 440C it will almost always be described as, or marked, "440C".
This is one of the primary differences between mass produced factory knives and handmade custom knives. Factories must use the milder steels for the stamping process. A custom maker does not have this restriction since each blade is cut by hand so a custom maker will almost always use the better cutlery steels.
When someone says that 440 stainless (or any stainless) will not take or hold a good edge, they are most likely comparing to a factory knife with a lower grade of 440 stainless steel. The fact is that there are a number of excellent stainless steels that will take and hold a great edge provided they are properly made and heat treated.
Another reason many of us use stainless steel is that is will take a great mirror polish. Mirror polishing is not just for looks. It will reduce cutting resistance and it is more sanitary and better for your blade and the sheath since a good mirror polish actually repels dirt and moisture. The blade will be much easier to wipe clean and transfer less crud into the sheath where it would be held against the blade. (Yes, even stainless steel will rust. It is rust resistant but not rust proof.)
Some say a mirror polished blade is too pretty to use. Nonsense! A good mirror polish will hold up much better than most people think. Yes, with use, you will get shallow scratches on the blade but so what? It will still provide the advantages described above and still look better than you might imagine.
A good example is the hunting knife made by friend Cliff Fendley from 440C stainless. I use Cliff's example because this happens to be one of the most used and carefully documented 440C knives I know of.
Yes, this is exactly how this knife looks after field dressing 21 deer over the last 5 years. It has not been re-polished since it was made in 2005. Nor has it been re-sharpened. Cliff just hits it with a few strokes on a croc stick to dress the edge when needed and it will still shave hair.
So if you are looking for a good reliable knife, don't discount stainless steel. Yes, there are harder steels but remember that harder also means harder to sharpen. Actually this is another common misconception. Everything in cutlery steel is a trade-off. Harder = more brittle, softer = less wear resistance. A knifemaker seek the best balance of properties. Personally, I would rather have a knife dull than to chip or break. Dull can be re-sharpened, broken is broken.
Many knife steels (including some stainless steels) can be hardened up to a Rockwell hardness of 60-61 but they are usually draw tempered back to around 56-58 Rockwell hardness because it takes the stress out of the steel and it performs better.
In conclusion, there are a lot of great stainless cutlery steels available today. A lot of research and development has gone into producing modern steel alloys. Every year there are new "super steels" introduced to the market. A lot of the super steel hype is just that, hype, but that doesn't mean it's not a good steel, maybe just not the end-all, be-all steel that the manufacturer claims. 440C stainless has been around a long time and it has stood the test of time to earn it's status as a tried and true very good blade steel.