Hi, friends!
By working on my Jeep, I had a problem with holes in diameter of 1,6 mm and was looking for a better solution of hollow punchs. I found a solution by tools, which are using for professional diecutting tools. They have a inside cone. So it is very easy to place them exactly over the printings.
By testing them, I have made some pictures:
First picture show the work with a standard hollow punch. I don't use a hammer for this work, but encroach my bench drill as a small sqeezer.
The second hole was made with the new punching tool.
The result is self-explanatory.
Both holes should have a diameter of 2,5 mm, but only the new tool made it. The outcutted piece have an interesting form, I used such pieces to make the valves of the tires for the jeep.
Where light is shining, there is also shadow. You have to use much more force for the punching tools with the inside conus, because there is no place for the suppressed material, the only way is to compress it.
For using it in optimal way (mainly for holes with a greater diameter than 5,0 mm), it is necessary to use a gear rack press (1 to) or something else.
I'm now the owner of a complete set of the new punching tools in diameters of 2,0 to 25,0 mm in steps by 0,5 mm.
Servus
Josef