Stamping is a general term that encompasses a broad range of metal forming capabilities and industrial uses.
Sometimes referred to as metal pressing, it is classified as a cold forming or cold working process, meaning it is usually done at room temperature.
The Deep Drawn Stamping Process
The stamping process is considered deep drawn stamping, or deep draw, when a part is pulled (drawn) into a die cavity and the depth of the recess equals or exceeds the minimum part width.
Deep drawing uses radial tension-tangential compression to shape the metal. This process transforms flat sheet metal, or blank, into a hollow vessel that may be cylindrical or box-shaped, with straight or tapered sides or a combination of straight, tapered and curved sides.
The vessel is then redrawn through a series of dies, reducing its diameter and increasing its length with minimal change to the wall thickness.
Deep Draw Stampings Modifications
This form of stamping usually involves other forming operations to complete the part such as:
Beads, Ribs and Flanges: often used to impart rigidity to a part which otherwise might be too flexible and weak. Their judicious use may reduce required material thickness by as much as 50%.
Bulging: the process of expanding the walls of a cup, shell or tube with an internally expanding segmental punch or a punch composed of air, liquids, semi-liquids or of rubber and other elastomers; this expansion may be symmetrical or nonsymmetrical.
Coining: a closed-die squeezing operation in which all surfaces of the work are confined or restrained.
Curling: forming an rolled edge at the open end of a part.
Dimpling: localized indent forming, so as to permit the head of a rivet or a bolt to fasten down flush with the surface of the metal.
Embossing: a process that produces relatively shallow indentations or raised designs with no significant change in metal thickness.
Extruding: turning up or drawing out a flange around a smaller hole; also called “hole flanging.”
Holes: a shaped portion of metal is cut from the drawn part using conventional, extruding, or piercing punches.
Ironing: operation in which the thickness of the shell wall is reduced and its surface smoothed.
Marking: process to add identification such as numbers, letters or graphics to a part.
Necking: reducing the diameter of a portion of the length of a cylindrical shell.
Notches: shaped notches that are cut from the edge of the part; usually provided for clearance, locating or attaching.
Threading: threads are formed on a part using a wheel and arbor, tap or die.
Trimming: cutting scrap off a partially or fully shaped part to an established trim line.