I am Juha S. Perttula, a Finnish scientist and knife maker. I forged my first knife from a six-inch iron nail when I was five years old, and two decades later, I earned a doctor’s degree in metallurgy. Then my professor allowed me study knife steels in his laboratory. I found that outperforming the cutting ability of quite simple carbon steels was extremely difficult, particularly when hardened to exceptionally high hardness levels. However, hard steel is often brittle. Thus, I have studied for thirty years how to make hard steel that is also tough. I have developed carburizing steels for engine gears and high-strength steels for bolts, but I have always worked with knife steels. I like hard and sharp blades. In addition to knife making, my goal is to complete my book explaining how to make extremely hard and tough carbon steels blades. This topic still holds many secrets.