The two most common ways to engrave metal parts are laser engraving, and CNC engraving. The same general principles apply, but they are two different machines, and mark the parts differently.
Engraving Machine Manufacturers Suppliers
3D Deep metal laser engraving machine with EZCAD3 software - Fiber
Engraving on Leather Items - getting started! - EnduranceLasers
Everything You Need to Know About Laser Engraving
COMGROW 5/10W CNC Laser Engraver Kit High-precision FAC Laser
Laser Engraving & Etching Services I Superior Laser Marking
Laser Power: 60W . Marking Area(Lens): 150*150mm (5-29/32) @ Jollystar.Engraving Depth:≤1.2mm(0.047in).Galvo: Sinogalvo 7110. Control Card
Double-Purpose Handheld Fiber Laser Engraver with 150mm(5-29/32) Opex Lens 60W JPT MOPA M7 Color Fiber Laser Engraving Machine for Metal Large or
CNC Engraving vs Laser Engraving: Discover the Difference
Everything You Should Know about CNC Engrave