What size was the tamping iron that went through Phineas gage head?

The tamping iron that went through Phineas Gage's head was 43 inches long and 1.25 inches in diameter at the thick end.

It's important to note that the size of the iron is often misrepresented, with some sources claiming it was much larger. However, accurate measurements taken from the original iron, now preserved at the Warren Anatomical Museum at Harvard Medical School, show these dimensions.