around the time of elementary school i had a ~15cm diameter steel (or may be something harder given where it came from - i didn't pay attention what it was made of, it was just pretty heavy) ball from a ball bearing from a driveshaft of a Navy ship. While not tungsten, it was still pretty great toy. We even played soccer using it - the style is very different as just strongly hitting it with or trying to abruptly stop with a foot would only cause pain to the foot, and the ball also would naturally not fly far :)