Bob Engelhardt wrote:

I recently mushroomed the end of a steel shaft using a brass hammer.

So you need a copper hammer. Never (with some caution) managed to ruin
the end of a thread.


Nick
--
Motormodelle / Engine Models:
http://www.motor-manufaktur.de
Ellwe 2FB * VTM 87 * DLM-S3a * cubic
more to come ...