#030 Basics of Die Structure (5) Structure of Hole Punching Dies - 2 (Hole Punching Die of the Fixed Stripper Structure)
In the case of a product that does not require high accuracy in hole punching work, very often the fixed stripper structure is used because it offers ease of operation. For example, when a hole is to be punched at an end of a long product as is shown in Fig. 1, it becomes easy to do the work if a fixed stripper structure die is used. As can be understood from the figure, it is easy to the work because it is sufficient to insert the material inside the stripper and carry out the work when the material butts against the end.
However, if the gap between the stripper and the die is large, although setting the material inside the die becomes easy, the punch gets fanned during stripping and becomes susceptible to breaking. It is better keep the gap small.
Since there is no pressing down of the material during hole punching, deformations such as warping can occur easily in the material. This is not suitable for punching holes close to the outer shape.
Apart from the above methods of use, this is also used frequently for the hole punching of bent products or drawn products. In such formed products, since the periphery of the hole to be punched is quite strong, very often there is no need to keep the material pressed down.
Hole punching need not be done only in flat surfaces, but sometimes it is necessary to punch holes in curved surfaces. In such situations, even the deformation of the area surrounding the hole is small, and very often it is sufficient to take care only about stripping and in a large number of cases the fixed stripper structure is quite satisfactory.
Although the basis of hole punching operation is punching the hole while keeping the material pressed down, depending on the conditions, there are products in which there is no problem even if the material is not kept pressed down and a simple structure can be used. Care should be taken because the easy of preparing the die and cost change depending on your judgment and decision.


- #167 Problems in Punching and their Countermeasures (6) Scrap Processing in Punching
- #166 Problems in Punching and their Countermeasures (5) Trimming of Drawn and Shaped Parts
- #165 Problems in Punching and their Countermeasures (4) Scrap Clogging in Punching
- #164 Problems in Punching and their Countermeasures (3) Bending and Twisting of Narrow Punched Parts
- #163 Problems in Punching and their Countermeasures (2) Bending due to Punching

