How precisely is "Steel Man" different from "Iron Man" in a debate?

Question

In a debate, Steel Man technique has been touted as the antidote of committing the Straw man fallacy. It doesn't appear to be a fallacy, but a virtue. Then I came across the Iron Man fallacy, analyzed and compared in this paper with 3 forms of the Straw Man fallacy: straw, weak, and hollow man.

Both seem to involve making the opponent's argument stronger, but one is a virtue and the other fallacious. My question is: When does Steel manning becomes Iron manning or vice versa? What exactly is the core difference between the two?

Answer 1

In the very first paragraph, the authors write:

We will argue that there are both appropriate and fallacious versions of this tactic [iron-manning].

They explain:

There are compelling epistemic reasons to regularly iron man one’s opposition, as the truth will come out in contexts of maximally responsible and detailed argumentation. Since our epistemic objectives in argument are truth and its understanding, the most intellectually robust opponent is the best, and if one does not encounter but must construct such an opponent, then so be it. Moreover, there are ethical (and political) reasons why iron-manning may be appealing. At its core, iron-manning is a form of interpreting others communicative acts with charity. The demands of recognition, further, for underrepresented groups obtain so that their interests can be heard and have effect. Iron-manning is in the service of this. Finally, again, there are pedagogical reasons why iron-manning may be required.

From the above, it seems clear they are just using the term "iron manning" as synonymous with "steel manning." There are right ways to deploy the technique. However, they go on to argue that there are also fallacious uses.

In all, we’ve identified a few rough criteria for knowing when iron-manning is fallacious:

1. When it is clear that the argument to be reconstructed is not likely to be either relevant or successful.
2. When it is clear that the improvement of and response to the argument will take more time than is allotted, and there are other, more clearly salient, issues.
3. When, even if 1 & 2 do not obtain (that is, when there may be something relevant and there is plenty of surplus time and energy), it is clear that responding to this speaker under these circumstances encourages further badly formed arguments.
4. When the positive reconstruction of the argument (iron man) in question yields mis-portrayal of the arguments prior critics as attacking a straw man.

For what it's worth, I've at least one other source reserve the term "steel man" for the appropriate use of this tactic, and "iron man" for a disingenuous use of this tactic (although, for "iron man", it cites to a blog post by John Casey, an author of the article you're asking about, so even he has waivered as to whether he draws a clear distinction between steel- and iron-manning).

But the labels don't matter. What matters is that there are appropriate and inappropriate uses of this kind of bolstering.