According to our 2017 State of Hardware Report survey participants, the second most useful website in existence is YouTube. Not surprising—where else are you going to find a quick CAD tutorial, learn about manufacturing, and watch a blender shred a brand new iPhone?

As such, we’ve compiled a list of YouTube videos that show how springs are manufactured, to round out our series on spring design (for more on custom spring design, and off-the shelf sourcing, be sure to check out part 1 and part 2). Be warned, it’s a black hole. Once you get into it, kiss your productivity goodbye. For best results, clear your schedule and watch alone in a dark place.

The holy grail of all manufacturing video series is How It’s Made. Unsurprisingly they have an episode on springs. It’s a great introductory video showing manufacturing of cold-coiled springs, which means that the wire is coiled at room temperature into coiled springs and other types of wire forms.

The video doesn’t show the heat treating and quenching process, which is done after coiling for strength and memory set-in.

This is my favorite video of all time. The music more than makes up for the lack of narration.

Springs with large wire diameters are hot-coiled. This means that the wire is first heated up to achieve austenization, and then it’s coiled and quenched. This video shows those three essential steps, as well as finishing operations.

If heat excites you, here’s another hot-rolled spring video. The spring in this video is as tall as me: five-foot tall free length!

Of course, not all springs are made of round wires. Flat springs can be made on a wire coiling machine, as well.

Watch, enjoy, repeat! And for more on how to actually design and sourcing considerations for springs, visit the Fictiv Hardware Guide.