People in submarines eventually need to sit down, and in 1944 aluminum company ALCOA collaborated with the U.S. Navy on the purpose-built 1006 Chair, also known as the Navy Chair or Submarine Chair. The design brief had at least one interesting bulletpoint: The chair had to be "torpedo-proof."
The resultant super-strong chair is still in production today, manufactured by aluminum chair company Emeco. For a fascinating look at how it's made, check out their 77-step process, starting from aluminum sheets and ending up with the finished product:
The video above is eight minutes and should be of interest to ID'ers because they call out each production method with on-screen notes. For those of you who already know this stuff, there's a frothier, shorter video using the same footage but edited down to about three minutes, sans call-outs, and scored with a jazzy soundtrack: