The use of pinch trim dies has eliminated the need to machine the ends of many drums and drawn washers; reducing the cost of these parts by almost $1ea.
2. You can machine it square or with some other geometry
3. You can use a pinch trim in the die
A regular formed edge may be acceptable in many instances, however it produces a very inconsistent edge over the profile of the part as you can see from the image below.
To counteract this inconsistency in the run out, the parts are often machined. Below you can see the before and after picture of this same part.
You can also change the geometry of the edge from a rounded…
to either a square or some other geometry machined into the edge.
The final option is the pinch trim. This method can provide a uniform profile and run out, but does not require a secondary (and often expensive) operation.
