Coining Sheet Metal Bending

Coining is a very basic type of bending in which the work piece is stamped between the punch and die.

Coining sheet metal bending.

Used for creating v u or channel shaped bends in ductile material usually sheet metal bending is a basic manufacturing process. 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. It is important to make sure that the sheet is properly pushed onto the wipe die. The tonnage required by coining is 5 8 times higher than bottom bending.

This method produces excellent accuracy and repeatability and does not require sophisticated machines to execute. The material is put under enough pressure that the punch tip penetrates the material and it begins to flow into the die. Both compression and tension occur when bending sheet metal. Operators use a press brake that features a punch and die to form the metal into specific angles.

Unlike in coining punch tips never fully contact the workpiece in air bending. A simple round metal slug is placed into the die and forced to flow into a given shape by compressing it see figure 3. Coining dies create the part s shape by squeezing the metal under extreme pressure. The inside radius of the bent metal is in compression or being squeezed together.

Coining is one of the most popular bending methods used in metal fabrication today. In this process the sheet or plate lays down flat on top of a die. The outside bend radius is in tension or being stretched. The coining not only featured high accuracy but also very small ir of the workpiece.

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. Wipe bending or edge bending is another way to bend sheet metal edges. Both the punch tip and the punch actually penetrate into the metal past the neutral axis under a high amount of pressure. As a result the wipe die also determines the bend s inner radius.

In coining the sheet metal is not just been bent it s actually tinned by the compress between the punch and die. The slack between the wipe die and the punch plays an important role in getting a good result. Air bending and coining are two of the most commonly used bending processes. Bending can be defined simply as a forming operation in which the metal is deformed along a straight axis.