The materials, equipment, and processes used in the metal stamping industry have proven to be less costly than the original methods of forming metals and alloys into definite shapes. Metal stamping is the method of bending, clipping, and molding sheet metal or coil metal by stamping and pressing the material into the desired forms. The shaped metal is plated with nickel, tin, or some other metallic elements to protect it from corrosion. The most commonly used metals are steel, aluminum, zinc, and nickel. They are low cost, strong, durable, hard to break, portable, and non-toxic.
The precision machining industry in North America has been on the decline due to two factors: the chronic inflation in the price of raw materials and the transportation of same, and a high level of outsourcing to China and India. Outsourcing hasn't struck the metal stamping industry as profoundly thanks to the proximity of the Great Lakes, around which it is concentrated.
The fire-and-brimstone method of forging is harmful to the environment, costly, and hard on the employees. Forming metal this way requires making the steel semi-molten so if the temperature is not estimated correctly (the workers would guess by experience decades ago) when the forge drops there are often rejects that have to be set aside, reheated, reworked, or scrapped altogether, slowing production. In a drop forge, the operators' work environment is a smoking furnace and rhythmic dance of the bars of metal shoot in one side and out the other. Fortunately, there are no ovens or blinding red iron to gaze into when inside a metal stamping factory. Industries that generate large amounts of environmental waste have largely been outsourced to poorer countries.
The major products of the Metal Stamping Industry are things like automotive muffler parts, finer components of larger machinery, equipment and larger metal structures. A common item like a Teflon frying pan would originate from a metal stamping plant, as would oddly-shaped metal containers with edges and rounded bottoms (difficult forms) that you would commonly see in a cafeteria...those deep fryers made of stainless steel have an unusual shape that would be too expensive to make with die-casting. They are deeper than they are wide and known in the industry as deep draws. Deep drawing would be done by metal stamping in a facility that does custom work or can set up for such orders.
There are two branches of the industry, defined by the presses employed by the particular company. The two sections into which the metal stamping Industry is segregated are Mechanical and Hydraulic Metal Stamping. The force produced by hydraulic presses is programmed and are best used for doing the aforementioned deep drawing because they can apply full tonnage over the complete length of the stroke. A hydraulic press is powered by a hydraulic pump to a cylinder or cylinders that drive the slide down. With the pressure preset, a valve can activate pressure reversal so no overload can occur. With this press design and its applications, the die tends to guide the press, so the guiding systems do not have to be as accurate as with a mechanical press that uses a progressive die. A die is a press tool with upper and lower halves that come together under pressure to create the shape of the metal. The upper member is attached to a slide and the lower one is bolted to the "bed" (also called a "bolster").
Mechanical presses use a mechanical flywheel that can stock up the energy needed to deliver the right amount of force for when it's time to punch or pierce the metal. If the production runs call for shallow drawing and blanking at much higher speed, mechanical presses would be used rather than hydraulic presses.
In addition to gap and straight-side presses, the shop would also require press controls and automation, coil handling and feeding equipment, safety equipment, light curtains, ram block, brake monitors, lifts and tilts, conveyors, transfer systems, machinery mounts, press mounts, and rotating cam limit switches. The metal stamping industry is critical to make parts for manufacturers - having the right kinds of equipment and knowledge means high production and cost-effectiveness. All of this equipment means that you can have a muffler on your car and enjoy a drink from a deep-drawn aluminum pop can.
