Donut-Hole Dies
We also stretch the limits of this type of die technology with ‘donut-hole’ dies, which cut a part with a hole in the middle. Conventional two-piece die sets are more practical and economical for round holes, but for most other shapes, this type of die is much less costly. The peace sign shows the extreme limit of what detail can be achieved with this method. A simpler version is used for cutting holes in existing parts, but has the same drawbacks as the full donut die. Both of these types are much more costly than a basic die for a solid shape of similar design, and are not as simple to use as the basic cutting dies.
It is possible, but not entirely practical, to get this type of die technology to cut a part with a hole in the center. The biggest drawback is that the part being cut becomes trapped between the two die plates that cut it and it’s hole from opposite directions. For simple shapes it can be more practical and economical to consider conventional two-piece die sets. Roper Whitney Co. has reasonably priced small manual equipment and tooling available. The pancake method can be a lot less costly for fancier designs.