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). Discuss your requirements for custom forgings with OEM Sales before making that critical decision. Call us to discuss your concerns.

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.

There are basically four methods (or processes) to make a forged part.

1. Impression Die Forging
2. Cold Forging
3. Open Die Forging
4. Seamless Rolled Ring Forging

Impression Die Forging

Impression die forging pounds or presses metal between two dies (called tooling) that contain a precut profile of the desired part. Parts from a few ounces to 60,000 lbs. can be made using this process. Some of the smaller parts are actually forged cold.

Cold Forging

Most forging is done as hot work, at temperatures up to 2300 degrees F; however, a variation of impression die forging is cold forging. Cold forging encompasses many processes -- bending, cold drawing, cold heading, coining, extrusions and more, to yield a diverse range of part shapes. The temperature of metals being cold forged may range from room temperature to several hundred degrees.

Open Die Forging

Open die forging is performed between flat dies with no precut profiles is the dies. Movement of the work piece is the key to this method. Larger parts over 200,000 lbs. and 80 feet in length can be

Seamless Rolled Ring Forging

Seamless rolled ring forging is typically performed by punching a hole in a thick, round piece of metal (creating a donut shape), and then rolling and squeezing (or in some cases, pounding) the donut into a thin ring. Ring diameters can be anywhere from a few inches to 30 feet.

Forging Advantages

Part Integrity

1. Directional Strength
By mechanically deforming the heated metal under tightly controlled conditions, forging produces predictable and uniform grain size and flow characteristics. Forging stock is also typically pre-worked to refine the dendritic structure of the ingot and remove defects or porosity. These qualities translate into superior metallurgical and mechanical qualities, and deliver increased directional strength in the final part.

2. Structural Strength
Forging also provides a degree of structural integrity that is unmatched by other metalworking processes. Forging eliminates internal voids and gas pockets that can weaken metal parts. By dispersing segregation of alloys or nonmetallics, forging provides superior chemical uniformity. Predictable structural integrity reduces part inspection requirements, simplifies heat treating and machining, and ensures optimum part performance under field-load conditions.

3. Impact Strength
Parts can also be forged to meet virtually any stress, load or impact requirement. Proper orientation of grain flow assures maximum impact strength and fatigue resistance. The high-strength properties of the forging process can be used to reduce sectional thickness and overall weight without compromising final part integrity.

Part Flexibility

1. Variety of Sizes
Limited only to the largest ingot that can be cast, open die forged part weights can run from a single pound to over 400,000 pounds. In addition to commonly purchased open die parts, forgings are often specified for their soundness in place of rolled bars or castings, or for those parts that are too large to produce by any other metalworking method.

2. Variety of Shapes
Shape design is just as versatile, ranging from simple bar, shaft and ring configurations to specialized shapes. These include multiple O.D./I.D. hollows, single and double hubs that approach closed die configurations, and unique, custom shapes produced by combining forging with secondary processes such as torch cutting, sawing and machining. Shape designs are often limited only by the creative skills and imagination of the forging supplier.

3. Metallurgical Spectrum
Forgings can be produced from literally all ferrous and non-ferrous metals. The forging process itself can be adjusted-through the selection of alloys, temperatures, working methods and post-forming techniques-to yield virtually any desired metallurgical property.

4. Quantity and Prototype Options
Virtually all open die and rolled ring forgings are custom made one at a time, providing the option to purchase one, a dozen or hundreds of parts as needed. An added benefit is the ability to offer open die prototypes in single piece or low volume quantities. No better way exists to test initial closed die forging designs, because open die forging imparts similar grain flow orientation, deformation, and other beneficial characteristics. In addition, the high costs and long lead times associated with closed die tooling and set-ups are eliminated.

Economic Advantages

Cost Reduction

1. Material Savings
Forging can measurably reduce material costs since it requires less starting metal to produce many part shapes.

 2. Machining Economies
Forging can also yield machining, lead time and tool life advantages. Savings come from forging to a closer-to-finish size than is capable by alternative metal sources such as plate or bar. Less machining is therefore needed to finish the part, with the added benefits of shorter lead time and reduced wear and tear on equipment.

3. Reduced Rejection Rates
By providing weld-free parts produced with cleaner forging quality material and yielding improved structural integrity, forging can virtually eliminate rejections.

4. Production Efficiencies
Using the forging process, the same part can be produced from many different sizes of starting ingots or billets, allowing for a wider variety of inventoried grades. This flexibility means that forged parts of virtually any grade can be manufactured more quickly and economically.