Thread: Stainless Steel

Chander has it correct. Being somewhat of a metallurgist I can tell you that each type of steel (stainless types included) has a solidification (or cooling) curve that tells you roughly what type of steel crystals will form by how rapidly you cool the steel (also known as tempering).

In other words, tempering makes the single largest difference in quality of a finished steel product, after the actual chemical makeup. And since steel is pretty well coded by the amount of carbon and any other metals present, it's pretty easy to know what type you are working with. Whereas in the old days, the purpose of folding steel together, was not to produce damascus or pattern welded steel, but was rather to mix two types to provide a superior carbon steel (high carbon and low carbon steels mixed).

If everything I said was too confusing, just remember: don't buy knives based on the type of steel only, buy them for who makes them. A better tempering process means better finished product, and you can bet that reputable companies do this reliably.

Also some of the questions to Robert above me:

"440C has a pretty high tempered hardness up to RC65?
Is 440C a brand or a mixture."

440C is a type of steel, not a brand, it stands for both the chemical composition as well as the type of crystalline structure that makes it up. In this case it means that it contains a low amount of nickel and higher amounts of chromium, though I can't remember the exact amounts. As Seraphim says above, it's commonly used in high-grade cutlery.

"For scary sharp is harder better? Up to what point?"
In general harder is better for edge retention and sharpness. Up to what point? Well until the steel becomes too brittle that it cracks when tempering, or under a slight amount of pressure. Also keep in mind that the harder steel is, the harder it is to hone. As with most things in life, it's about balance.