A crowbar is a metal tool used mainly to pry things open. It is usually hook shaped. Sometimes the bottom is slightly curved to allow for better leverage. Some crowbars have a notched an end for removing nails. Crowbars are often made of carbon steel. They can also be made of titanium which is lighter and non-magnetic. The first known use of the word was somewhere in the 1400s where they were simply called crows or iron crows.
It is used as a lever either to force apart two objects or to remove nails. Crowbars are commonly used to open nailed wooden crates. Common uses for larger crowbars are: removing nails, prying apart boards, and generally breaking things. Crowbars can be used as any of the three lever classes but the curved end is usually used as a first-class lever, and the flat end as a second class lever. In mining, crowbars are used to break blasted rocks and to remove loose rock on roof sides and the working face, but not much in modern mining.