The Difference Between Bottom Die Attached and Open Die Forging

When a metal is bent into various shapes and sizes, it is called die for cutting. The process of dying for cutting involves drawing a metal piece with compressive forces so that the shape is changed. There are many uses of die for cutting metal since it can be used for bending, twisting as well as punching. Some of the common types of die for cutting are cut-out, plate for piercing, flanged die as well as grooved die for cutting wide areas. When the pieces of metal are cut to required shapes using dies for cutting, the pieces are often pressed together at a die press or even welded.

While Open Die Forging limits the working area of the dies, open die forging is characterized by the fact the metal between multiple dies is not completely enclosed or confined in the dies themselves. Often, the process of open die forging is done on horizontal steel dies. Then, the pieces of metal are fed into the die with the help of a die press. This process is sometimes coupled with tumbler operations.
In the case of an H-frame design, the forged metal is fed into the die using a vertical shaft that has been fitted into the vertical blank shaped like a hanger and is then struck against the oblong shaped block at the top of the H-frame. The depth of the strike depends on the type of metal being used in the blocks. The depth can be determined indirectly, for instance, by measuring how much of the metal goes into the die after it is struck.
Open die forging and closed die forging are used to create various types of tools such as press brakes, valve seats, valve trim, seat blocks, seal blocks and camshafts. However, there are some advantages of each of these processes. With open die forging, for example, the machining operations are simpler because there is less material to remove, which means faster cutting speeds and less wasteage of costly materials.
On the other hand, with closed die forging, the process of making the tool does not require removing material from the surface of the die, which means faster cutting speeds but greater force use. Also, in open die forging, the tool may come in contact with more than one die, for example, if the tool is used on a pressing press. In such cases, the chance of surface erosion is higher because the number of edges and patterns in the pressed formation are greater. Also, since the tool is in motion, the speed of the formation of new dies is also faster.
The variation between open die forging and bottom die attached is not very big, so it is difficult to notice the main difference when two or more metal parts are pressed. But it is easy to observe the main advantage of the latter: it uses less metal. Since a tool works by moving the metal round an axis, it usually requires fewer materials, and the number of processes needed to create the same design increases. Because of this, forge hammers usually have a smaller footprint than the traditional impact drivers and pneumatic hammers.