this may not be exactly what your looking for, but I recently made a set of gravers from old worn out 3 corner files. keeping in mind that yes the angles have got to be right in order to work, they have gone through a few of my test passes with out chipping (as some may say is going to happen because I didn't mess with the ht of these files). the tips are holding out decently. I should say that I am doing this as a hammer engraving process.
originally I made these to do inlay work in the future, but I've had some really surprising success with what I think is called the Lindsey style of points. I don't have the angles prefect, which leads me to believe that you can have some play with these tools, although, each bevel has to be pretty consistently equal to its opposite side.
I got some pictures of my work with a crummy camera - these are some of my first attempts at actual hammered engraving. the tools are not exact to the Lindsey style but their following his examples.