We use the term steel knife in this article. However, most of the information applies to steel in general. Steel is iron with no more than 2% carbon. The higher the carbon in the most difficult of the steel blade can be made. The steel harder than the sharper the knife's edge can take. The quality of heat treatment on steel knife blade has a great influence on the force. With lower-quality steel properly heat the result is a blade that is stronger than a knife blade heat treatment of high quality steel that was wrong. Most tempered martensite steel knife with a fine grain structure with lattice irregularities is difficult. Several elements can be added to steel to produce different properties. What follows is a list of items often added to steel knife and its purposes. Carbon: This is the most important addition to steel of tempered steel. In case of steel sheet of more than% carbon, which is a high carbon content. Carbon usually means little or no alloying ingredients are added. Sheet steel with a high carbon, low chromium but is susceptible to rust and pitting if not kept dry and oiled.Chromium: This is added for hardening, and to increase resistance to abrasion and corrosion. Steel knife at least 13% chromium stainless steel is considered. Cobalt: Cobalt is added to the steel blade to increase strength and hardness. The cooling at high temperatures authorizations and intensifies the individual effects of other elements in more complex steels. Copper: Copper is added to increase resistance to corrosion. Manganese: Manganese is added to steel as the knife to support the grain structure and increases the ability to harden steel. It also increases the strength and wear resistance. Manganese is present in most cutlery steel. Molybdenum: This element prevents brittleness in the steel knife and steel helps maintain resistance to high temperatures. It is the smallest size iron and hardness toughness.Nickel: Nickel improves start-steel blade to increase strength, corrosion resistance and strength of steel. The corrosion resistance term is used by all samples eventually corrode if not cared properly.Nitrogen: Nitrogen can be used instead of carbon steel knife. The nitrogen atom is similar to carbon but offers the advantage of resistance to corrosion. Silicon: Contributes to the strength of steel sheet. Tungsten: Tungsten is added to steel knife to improve strength, endurance and toughness of the steel.Vanadium knife: Increases resistance to abrasion and ability to harden steel plate. Molybdenum is only the smaller the grain size in the iron hardness and toughness of steel for improvement. There are different types of steel are often used by leading manufacturers in their leaves. D-2, 420, 440, 425, COL. These types of steel sheet and others will be discussed in another article.