Only slightly off topic I recently get to know about a technique in (industrial) manufacturing, friction forging: https://www.diamondbladeknives.com/Friction-

Only slightly off topic I recently get to know about a technique in (industrial) manufacturing, friction forging: https://www.diamondbladeknives.com/Friction-Forging https://www.diamondbladeknives.com/Friction-Forging cannot say if it actually delivers what it promises, but the video is interesting.