I'm just curious how you know where the bolt you broke was made.

Interesting. So, if there is a manufacturer in the US and one outside with the same name, how does one know which is which? Looks like SAE J429 might have the answer but don't know how to get a copy of that. And would like to add, if the running board company I purchased from IS using the US based hardware supplier, kudos to them!
All depends if they have a fine print stating *some custom work may be required*Well, the diytrade link above looks like it is purely a buying site (ebay/amazon/alibaba/etc). It mentions WTF Co, LTD, but upon further investigation WTF CO is actually a food distributor in Bangkok Thailand.
There could obviously be more to the story, but just like when a seller on Amazon states their part XYZ fits Ram 1500, 2500 and 3500 from 1972-current, I am hesitant to believe their listing.