... 3electro-magnet marking machine 4 metal engraving machine 5metal marking machine This kind of metal marking machines,with electromagnet, ... surface , esay to marking, electro-magnet marking machine, metal engraving machine, pin marking machineMarking Surface: Flat surface or ... depth0.02-1mm(adjustable,relevant to materials)Marking speed2-4 characters per second (to characters)Marking materialsMetals or ...