Knife has predominantly used for many purposes from a tool to a weapon. Most probably it must have been the first type of weapon or a tool. History shows us that it has been there for almost more than two million years. The foremost knife was carved out of a stone or a rock, obsidian and flint and had evolved into various forms as the earth went through different periods of evolvement. Knife is made from different metals like copper, bronze, iron, steel, ceramic and also titanium. Cultural and religious development had an effect in the development of knife to the current period. Each culture or society had their own prototype of their knife. Some knives had spiritual significance related to them.
Present day knives can be segregated into two groups namely the fixed type or the folding type. Knife as a device has a blade and a handle. Handle has a portion of the knife extended into it. Handle can be covered or bolstered with different materials like brass or other metals where it meets the portion of the knife. Blade of the knife has different area like the point, edge, gring, spine, fuller, ricasso, the guard and the butt. Each area of the knife has a specific function like the point is used for piercing; the butt is the end of the handle and so on. Each blade differs in size, shape and weight depending on the area of its origin and the purpose for which it is designed for.
Blade which forms the foremost part of the knife can be made with different material like carbon steel, alloys of iron like steel and stainless steel which have different properties. Carbon steel can be made very sharp but rust very easily. Stainless steel is difficult to sharpen but are very resilient and do not rust. There are knives made with high carbon stainless steel and laminate. In the former the knife has the best quality of both the carbon steel and stainless steel. In the latter many different metals are used to layer which makes the knife harder and less corrosive. Titanium is another material that is widely used in making knifes. This metal is more flexible, stronger and corrodes much less than any other material. They can be made very sharp and last for a long time. Knifes are also made from ceramic which are brittle and out of plastic which are not very sharp.
Knives have been used as a weapon, as a cutlery, tool and those that have religious significance. Knifes like bayonet, combat knife, throwing knife, trench knife all belong to the weapon category. Carving knife, oyster knife, bread knife, chefís knife are some examples of knives that are used as a cutlery. Pocket knife, diverís knife, hunting knife and paper knife are tools used for a specific purpose. Knifes that have religious significance are kirpan, kukri, kris, athame and kilaya.
Knives have existed for millions of years and have evolved along with the evolution of men and human have used technology to create beautiful knifes which are a work of art.