… by laser or other light or photon beam, ultrasonic, electro-discharge, electro-chemical, electron beam, ionic-beam or …
Explanatory notes
… laser or other light or photon beam, ultrasonic, electro‑discharge, electro‑chemical, electron beam, ionic‑beam or … for watches, etc.), machines for cutting metals or other hard materials and machines for engraving (figures, letters, … Water-abrasive jet cutting machines are typically used for harder materials (tool steel, hard rubber, composites, …