Coining Sheet Metal Bending

In coining the sheet metal is more than just bent it is actually thinned by the impact of the punch and die as it is compressed between them along the bending surfaces fig.

Coining sheet metal bending. The term coining comes from the idea that when it comes to money each metal coin is made exactly the same as the last despite being mass produced. The slack between the wipe die and the punch plays an important role in getting a good result. Both compression and tension occur when bending sheet metal. In coining the sheet metal is not just been bent it s actually tinned by the compress between the punch and die.

It is important to make sure that the sheet is properly pushed onto the wipe die. This method produces excellent accuracy and repeatability and does not require sophisticated machines to execute. Air bending and coining are two of the most commonly used bending processes. As a result the wipe die also determines the bend s inner radius.

Coining fabrication is a basic type of bending in which the workpiece is stamped between the punch and die. The outside bend radius is in tension or being stretched. Coining dies create the part s shape by squeezing the metal under extreme pressure. Coins metal currency are created with the coining process.

A simple round metal slug is placed into the die and forced to flow into a given shape by compressing it see figure 3. The material is put under enough pressure that the punch tip penetrates the material and it begins to flow into the die. Wipe bending or edge bending is another way to bend sheet metal edges. Unlike in coining punch tips never fully contact the workpiece in air bending.

In this process the sheet or plate lays down flat on top of a die. Bending can be defined simply as a forming operation in which the metal is deformed along a straight axis. Operators use a press brake that features a punch and die to form the metal into specific angles. Coining is a very basic type of bending in which the work piece is stamped between the punch and die.

The tonnage required by coining is 5 8 times higher than bottom bending. Coining also can reduce the metal thickness. Both the punch tip and the punch actually penetrate into the metal past the neutral axis under a high amount of pressure. Used for creating v u or channel shaped bends in ductile material usually sheet metal bending is a basic manufacturing process.