Milling copper.
Cutter with mechanical insert clamping: https://goo.gl/9X3eYn
Cutter inserts: https://goo.gl/hTA6Mt
6mm cutters: https://goo.gl/5Y91Lo
4mm cutter: https://goo.gl/mBGuve
CNC
Yekaterinburg
/ zigzag_blade
http://zigzag-blade.ru/