The most popular and the commonly used type of hand tool is the hammer used to deliver blows to an object or strike another object, in the sense that it is used for driving nails, fitting parts and breaking up objects. These hammers are available in various shapes and structures, hammers are designed for specific purpose. The hammer consists of a handle to which a heavy head, usually made of metal is attached, with one or more striking surfaces. The basic design of a hand tool is hand operated though there are also different mechanically operated designs for heavier uses.