Dies are used in manufacturing presses to cut, shape or stamp materials such as metals, wood, and plastics. Dies come in a variety of shapes and sizes, and can be customized based on how they will be used on a material. Typical examples are bending dies, forming dies, thread cutting dies, wire pulling dies, and so on.

Dies are used to develop cutlery, aluminum cans, automobile parts such as fenders and frames, zippers, buttons, screw threads, imparting finishes to items, embossing, coining, and making wires.

Parts of a die
Dies have upper and lower shoes, each of which can have various components based on usage. A typical die consists of the following parts:

• Die block: clamps the work piece in place for stretching, bending and blanking.
• Punch plate: is used with the die block for stretching, bending and blanking the work piece from the other side.
• Blank punch: is a shearing tool that punches out the needed section from sheet metal.
• Pierce punch: is a tool attached to the top part of a die shoe to pierce the sheet metal.
• Stripper plate: removes sheet metal stock from the punch during the punching process.
• Pilot: is a long rod that holds the metal in position by entering a pre-punched hole.
• Die retainer: is a steel block with impressions that are transferred to the sheet metal during punching.
• Guide post: is a rod that guides the punch during operation.
• Compound die: carries out more than one operation.

Types of die operations
Dies are used for various operations such as:

• Blanking dies cut out a flat piece of metal (called blank) in the desired shape.
• Bending dies  cut the blank at a predetermined angle, as in square corners
• Forming dies bend the blank in a curve.
• Roll forming: is a process of rolling sheet metal or strips to form a tandem roll of required cross-sectional width. 
• Bulging: expands one end of a tube to form a bulb. Bulging rubber dies or fluid dies are used for this purpose.
• Coining dies squeeze the blank into a confined area and transfer one design on its facing side and another on the side facing the punch.
• Drawing dies lead to excessive plastic deformation that causes the material to spread around the sides.
• Cut off dies are used to trim excess material off finished products or to cut materials to size for further operations.
• Curling: is the process of forming a material into a curly shape. Curling dies are used for this purpose.
• Extruding: Slugs are the discarded parts of punched materials. Extruding dies apply intense pressure from the punch to shape materials into desired results.
• Thread cutting die is a nut like cutting device to gouge screw threads into rods.
• Wire making dies have a hole in the center to draw out the wire.
• Hydro forming: is the application of intense water pressure to form tubular parts from tubes.
• Piercing dies are used to stamping holes.
• Shaving dies remove excess material from edges to finish to a product.
• Trimming dies cut away rough edges at the last stage of production.
• Swaging: is the process of constricting the cross-section of a material by necking it down. Swaging dies are used for this purpose.
• Sub pressing: is the forming or blanking of small parts such as parts of instruments, watches, etc. Sub pressing dies are used for this purpose.

Dies and die parts are manufactured by tools and die makers. The die itself is made of metal and is mounted on a press to form materials. The material processed by the die goes through many more manufacturing stages before reached its finished form.