Lets define some terms here before we begin.

A wrecking ball is generally a 2,000-15,000 lbs chunk of metal a crane swings around to destroy things. The earliest recorded uses of wrecking balls were in the 1930s, and although they are still used today the wrecking ball lost much of its popularity in the 1960s due to heightened awareness of the harmful toxins released into the air when structures are haphazardly demolished.

To forge: the act of heating up a metal and beating/striking it into a new shape while it is in its hotter, more malleable state.

Using these definitions, wrecking balls were never really forged, they were cast steel. The difference does not generally matter in casual conversation, but to be accurate the wrecking balls were poured into shape rather than welded and hammered. This is also why when inspecting a wrecking ball you will find no seams in its construction, it is made of one solid item. The metal required was melted in a furnace, and poured into a mold created for this purpose. It was then allowed to cool for an extended period of time due to its high density, and shipped off.

Although i was not able to locate any images or videos of wrecking balls being created (people seemed to enjoyed filming the wrecking ball while it was being used rather than created) I was able to locate some images of industrial smelters that would have been used to create the wrecking balls. Many of these smelters are still in use today, so if you would like to watch similar items being created you would likely be able to locate them online.

Image of large smelter melting steel block

Here is a site of a modern manufacturer of wrecking balls, it briefly describes the current process.

Edit: A comment that seems to have been deleted pointed out that welding is not necessary while forging items, which is true. I was trying to make an infeasible situation slightly less so by adding welding into the mix.

Hello everyone,

If you are a first time visitor, welcome! This thread is trending high right now and getting a lot of attention, but it is important to remember those upvotes represent interest in the question itself, and it can often take time for a good answer to be written. The mission of /r/AskHistorians is to provide users with in-depth and comprehensive responses, and our rules are intended to facilitate that purpose. We remove comments which don't follow them for reasons including unfounded speculation, shallowness, and of course, inaccuracy. Making comments asking about the removed comments simply compounds this issue. Additionally, insulting the mods for removing such comments isn't acceptable and could potentially result in a ban, as it already has for some. So please, before you try your hand at posting, check out the rules, as we don't want to have to warn you further.

Of course, we know that it can be frustrating to come in here from your frontpage or /r/all and see only [removed], but we thank you for your patience. If you want to be reminded to come check back later, or simply find other great content to read while you wait, this thread provides a guide to a number of ways to do so, including the RemindMeBot or our Twitter.

Finally, while we always appreciate feedback, it is unfair to the OP to further derail this thread with META conversation, so if anyone has further questions or concerns, I would ask that they be directed to modmail, or a META thread. Thank you!

https://www.reddit.com/r/AskHistorians/comments/8p0s9b/roundtable_21_be_kindremind_the_mod_approved/