I'm trying to take the same approach to knife making. I'd like to tell you how to transform a piece of appropriately chosen scrap steel into an excellent cutting tool without using a lot of expensive power tools. Even if you never use this information to make your own knife I hope that it will give you a greater awareness of what constitutes a good' knife. The ability of a knife to maintain a sharp edge after extensive use is a very valuable characteristic. There are two principal mechanisms which cause a knife to become dull, mechanical abrasion and chemical etching.
Mechanical abrasion is the main dulling mechanism in carving dry wood.
Both mechanical abrasion and chemical etching are important in meat cutting and shaving. Stainless steel razor blades last longer than the old plain carbon steel ones because they are more resistant to attack by the chemicals in the shaving cream. Edge holding is also intimately connected with the hardness of the blade. Hardness, defined as resistance to penetration, is a measurable quantity. One qualitative measure of hardness is the Rockwell C scale, based on an instrument which presses a diamond stylus with a specific force into the material being tested.