Bottom Bending Sheet Metal

Because the material is pressed into the bottom of the die the desired bend angle determines the specific die to be used.

Bottom bending sheet metal.

The solution is to have a radius on the tool that you ll be using to bend the metal. As the name bottom pressing suggests the punch presses the metal sheet onto the surface of the die so the die s angle determines the final angle of the workpiece. Bottoming is also known as bottom pressing or bottom striking. To bottom bend this material you would need an 88 degree punch and a 90 degree bottom the set angle to produce a bottomed bend.

And unlike coining bottom bending can reproduce an inside bend radius of up to three times that of the material thickness as well as a sharp inside bend radius. When bottom bending the die angle should match the intended angle of the work piece adjusting a few degrees for spring back hence the existence of 88 punch tooling to achieve 90 degree angles. Bottom bending the final category of sheet metal bending is known as bottom bending or bottoming in this method the metal sheet or plate lays flat while the top punch and die are brought together above and below the work using minimal tonnage. In bottom bending the punch and die never make full contact with the metal sheet.

Bottom bending is similar to coining when done properly except that tonnage is greatly reduced. Even on malleable materials you can end up cracking the metal at the bend or weakening it to the point where it ll break with minimal force. Air bending in this process the work piece is only in contact with the edge of the die and the tip of the punch. There are three types of bends used to form metal that any sheet metal engineer or press brake operator must be familiar with.

If you bend to a sharp inside corner with sheet metal you ll be adding a ton of internal stresses. With bottoming the inner radius of the angled sheet depends on the die s radius. The lower tonnage requirements are attributable to the angular clearance between the complementary angle of the punch and the included angle of the v die see figure 2. As an example if you want to bend 24 gauge sheet metal at a 90 angle the calculation would be.

How to bend sheet metal without a brake how to bend sheet metal without a brake in 4 different methods with minimal or homemade tools. Bottom bending requires more pressure generates less spring back and creates more accurate angles. To ascertain your k factor inside radius and material thickness expressed as a decimal you should use an bend allowance chart. By using the punch angle that bends the material to 92 degrees before it is forced back to 90 degrees you can compensate for having too much punch angle.

Bottom bending is the process of stamps the radius of the punch tip into the work piece. This differs from coining which puts the entire surface of the work piece under such tonnage that it begins to flow.