system
Given the following post, respond as if you're commenting on Reddit:
human
Askscience, what is one the most mind-bending things associated with your field?

Something that really makes your head hurt thinking about it.

Edit: of* sorry about the typo :/
gpt
The speed that metal deforms in metal cutting (milling, turning, etc) is well over 1000 times more rapid than the metal casings of even the most violent explosives. In fact, it is practically impossible to re-create these conditions with current or foreseeable technology.

Friction-stir welding; take a tool, plunge it into the seam of two metals and spin it to plastically deform them into each other; this is done at sub-melting temperatures and is ideally entirely mechanical with no melting of the metals.

Explosive welding and amour piercing ammunition: the forces involved are so high that the mechanical strength of the steels involved becomes negligible in modeling and calculations.