Songfacts®:

• This is the closing track of Metallica's tenth album, Hardwired... to Self-Destruct. Colombian radio station Radioacktiva asked vocalist James Hetfield whether the "Hardwired... To Self-Destruct" title was inspired by how people are connected to each other through mobile devices and how everyone is becoming more dependent on technology. He replied:
  
  "That as well. Sure. The song 'Spit Out The Bone', which is getting rid of the human flesh part. And machinery is so much more efficient. And ourselves as people, [we're] very… I don't know… We want things quicker, we want the convenience of technology, but at what point is convenience leaning into dependency, and we need it, or else we don't know what to do."
• The song's epic, dystopian music video was directed by Phil Mucci, who has previously worked with Korn, Disturbed and Stone Sour among others.
  
  "I was really nervous ever showing that to the band," Mucci admitted in a behind the scenes film. "I was nervous to show Metallica the rough cut of the video because it was terrifying. If I were them and I had read the treatment that promised all this really fun old school effects and puppets and robots and you get this green screen edit in which there's no robots, there's no puppets, there's nothing in it … so I waited until at least some of the pieces filled."
• The song originally ran close to 10 minutes. Metallica realized they needed to trim it, making it leaner and thinner, more concise. Lars Ulrich told Rolling Stone:
  
  "That was just an adventure, man. I have versions of that song that are two to three minutes longer. We just kept going and going and going. That was also the first song where we went, 'Wait a minute, is there too much of a good thing here?' And then we started peeling it back.
  
  It was one of those where you just keep going to different universes and different modes and areas because it was super fun. It was like this journey. Old-school Mercyful Fate–type stuff was kind of the inspiration for that."
• James Hetfield explained the song's meaning to Metallica's fan-club magazine So What:
  
  "This is a little different, just the wonder and fear of, again, what's happening to man. Without future tripping too much, just the possibilities of Terminator,stuff like that, you know. We're wearing smart watches, things are getting closer and closer to just being in us.
  
  "Why would I not have the internet in my head all the time? Why do I have to worry with all these 'emotions' and stuff? Falling in love and getting your heart broken? That doesn't do anybody good. You know, the heart and blood? It's in the way of efficiency! We could be a much more efficient race if we just allow computers to help us.
  
  "And yeah, they are helping us, but how far does that go? All of that craziness. So 'Spit Out the Bone' is that your bones aren't needed. They break!"
• Hetfield took the title phrase from UK street punk band GBH's 1982 track about the 1972 Andes flight disaster titled "Passenger on the Menu." The lyrics in question are:
  
  Had no choice, lost and alone.
  Eat the flesh, spit out the bone.
  
  On October 13, 1972 Uruguayan Air Force Flight 571 crashed on the remote Andean peak called Cerro Seler. Many died in the crash and several others quickly succumbed to cold and injury The 16 survivors were forced to feed on the bodies of dead passengers in order to keep alive.
  
  Hefieldt said: "Yeah, thank you GBH for the 'spit out the bone' line. I know their song was a little different. Their song was about the Donner Party and cannibalism."
• Metallica played the song live for the very first time on October 24, 2017 during their gig at The O2 Arena in London, England.