What was Metallica's working title for The Black Album during recording?

Metallica's working title for The Black Album was Married to Metal.

The phrase arose as a running joke connected with the personal upheaval surrounding the recording sessions. Kirk Hammett, Lars Ulrich, and Jason Newsted were divorcing their wives during the album's troubled production, and the provisional title reflected that situation with dark humor.

The band also considered “Five,” which would have emphasized the album's place as its fifth studio release, and even discussed using the title of one of the songs. They ultimately chose the simple eponymous title Metallica, following the band's preference for keeping the presentation direct.

The final cover reinforced the album's visual austerity: the logo and coiled snake were embossed against a nearly black background on the initial release. That design led fans and the music industry to adopt The Black Album as a nickname. “Married to Metal” therefore belongs to the album's development history, not its official retail title or a later alternate edition.