What is Forging?
Forging is manufacturing process where metal is pressed, pounded or squeezed under great pressure into high strength parts known as forgings. The process is normally (but not always) performed hot by preheating the metal to a desired temperature before it is worked. It is important to note that the forging process is entirely different from the casting (or foundry) process, as metal used to make forged parts is never melted and poured (as in the casting process).
Why use forgings and where are they used?
The forging process can create parts that are stronger than those manufactured by any other metalworking process. This is why forgings are almost always used where reliability and human safety are critical. But you'll rarely see forgings, as they are normally component parts contained inside assembled items such a airplanes, automobiles, tractors, ships, oil drilling equipment, engines, missiles and all kinds of capital equipment - to name a few.
Who buys forgings?
Forged parts vary in size, shape and sophistication - from the hammer and wrench in your toolbox to close tolerance precision components in the Boeing 747 and NASA space shuttle. In fact, over 18,000 forgings are contained in a 747. Some of the largest customer markets include: aerospace, national defense, automotive, and agriculture, construction, mining, material handling, and general industrial equipment. Even the dies themselves that make forgings (and other metal and plastic parts) are forged.
How big is the forging industry?
The forging industry is composed of those plants that;
a) make parts to order for customers (referred to as custom forgings);
b) make parts for their own company's internal use (referred to as captive forgings); or
c) make standard parts for resale (referred to as catalog forgings).
The largest sector - custom forging - accounts for over $6 billion dollars in sales annually. These custom forgings are produced by about 250 forging companies in approximately 300 plants across the U.S., Canada and Mexico.
How many people are employed by the forging industry?
Approximately 45,000 people from coast to coast are employed by the forging industry in the United States and Canada. Because the modern forging process is capital intensive (requiring an abundance of heavy equipment for manufacture and the people to run and maintain it), most forging plants are small businesses which generally employ between 50 to 500 employees each, with a few larger facilities employing over 1000 people.
What metals are forged?
Just about any metal can be forged. However, some of the most common metals include: carbon, alloy and stainless steels; very hard tool steels; aluminum; titanium; brass and copper; and high-temperature alloys which contain cobalt, nickel or molybdenum. Each metal has distinct strength or weight characteristics that best apply to specific parts as determined by the customer.
What kind of equipment is used to make forgings?
Although the styles and drive systems vary widely, a forging can be produced on any of the following pieces of equipment.
Hammers with a driving force of up to 50,000 pounds, pound the metal into shape with controlled high pressure impact blows.
Presses with a driving force of up to 50,000 tons, squeeze the metal into shape vertically with controlled high pressure.
Upsetters are basically forging presses used horizontally for a forging process known as "upsetting".
Ring Rollers turn a hollow round piece of metal under extreme pressure against a rotating roll, thereby squeezing out a one-piece ring (with no welding required).