The reported working title for Metallica's fifth studio album was “Married to Metal.”
The phrase came from a running joke connected with divorces involving Kirk Hammett, Lars Ulrich, and Jason Newsted during the album's creation. It was never used as the official title, and the band ultimately chose the simple eponymous name Metallica.
Other possibilities were considered, including Five and the title of one of the songs. The final decision to use the band's name matched the group's desire to keep the presentation straightforward.
The nickname The Black Album came later from the cover design rather than from the official title. Because the initial packaging used nearly invisible black embossing for the logo and snake, listeners began referring to the record by that informal name. “Married to Metal” is therefore a behind-the-scenes working title, not an alternate official album title.