I have a 4 inch 4140 steel cylinder I want to use for a beginner anvil, it weighs about a 100 lbs. It has not been heat treated. My first question is should it be heat treated? second question is if it should be heat treated, what is the recommended way to heat treat it as far as temperature and ideal way to cool it down, by dumping water on it or air dry. I have seen many different videos and articles of how to do it, most all of them are fairly different from each other.

Thanks in advance for the help.