What is Closed-Die Forging

In the closed-die forging process, metal blanks, or billets, are heated to perhaps as high as 2,200F depending on grade, and then either pounded by hammers or squeezed by presses with dies that contain an impression of the shape of the final forging. Closed-die drop forging is a popular process in the forging industry for the creation of tools, aerospace parts, turbine blades and other high performance steel parts.

How Closed-Die and Drop Forging Works

The hammer forging process is sometimes called drop forging. In drop forging, steam, compressed-air, hydraulic power, steam or rollers raise the ram to which the dies are attached and then drop it at high speed onto the heated billet. The energy for forging is provided by gravity, or assisted by the energy source used to raise the ram. Many blows may be used to provide a part with the final forge shape and dimensions.

Advantages of Drop Forging

The process of hot working metals has been used for thousands of years to improve strength, toughness, reliability and the highest quality. In casting, another metal forming process, the material is melted and then poured. The casting process does not provide grain densification or the grain flow delivered by forging that gives the part improved properties.

Once a part is tooled with impression dies to the specifications of the part to be made, consistent forgings can be made consistently and cost-effectively. Closed-die forging is the process commonly used to turbine blades, vanes, gear blanks, pinions, connecting rods, and other metal parts used in critical applications.

Limitations with Drop Forging

Size limitations often times can be barriers in the drop forging process. The larger the forging, the larger the forging hammer needs to be. Typically rated by the weight of the ram, Canton Drop Forge’s largest hammer is 35,000 lbs, making it one of the largest in the industry and capable of making parts up 3,500#s.

If your part is being used in a critical application where safety is important and failure is not an option, where piece-of-mind, strength, toughness and durability are essential to the performance of your part, drop forging is an ideal and cost-effective solution. Contact Canton Drop Forge to learn how our modern forging plant can produce your part on time and to your specifications.


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