Electric Discharge Machine
This is a little DIY electric discharge machining tool to mark metal things.
More infos at: http://www.nexlab.net/2016/05/30/stainless-steel-and-other-conductive-metals-electrical-marking
If you like my my work, plase consider donating to: [DONATIONS id:1360] http://www.nexlab.net/donations/diy-electroplating/