My friend Palmer Moynihan is my guest instructor today demonstrating engine turning. Sometimes called JEWELING. FROM WIKIPEDIA -----"Engine turning, also known as jeweling, is a fine geometric pattern that can be inscribed onto metal as a finish. Aluminium is often the metal chosen but any metal can be finely machined to produce intricate repetitive patterns that offer reflective interest and fine detail."
Do a google search for "Damaskeening".