Talk:Black oxide

The “Hot black oxide” section repeatedly refers to “bolts”. Is this just a specific sort of workpiece the text was written for (so the text should be generalized), or does the term have a specific meaning here? —— Unbitwise (talk) 15:26, 27 November 2011 (UTC)

History of the process?
I was hoping to look up when black oxide was developed & popularized but this article and the related one on bluing appear to be focused only on contemporary processes. This is pretty far outside my wheelhouse but is there info on the history of black oxide? ~ oulfis 🌸 (talk) 03:46, 21 June 2021 (UTC)