Stainless steel laser engraving machine generally use fiber lasers, laser engraving can be in a variety of metal and some non-metals, including mild steel and stainless steel, inconel and titanium. Since the optical fiber laser has a fast pulse rise time and high beam quality and therefore particularly suitable for metal marking. This laser can be used with galvanometer marking head combination forms a pocket-sized packaging systems. On the metal marking commonly used 20W fiber laser, from the time when the material factors focused laser beam, due to the formation of surface oxidation discoloration mark, mark type is formed by laser energy input, marking protective gas and materials and other decisions . Because the marking on the metal is a high energy process, and therefore smaller spot size, the shorter the focal length, the quality of play, the higher mark, marking cycle is relatively short. But To reduce the cost of the entire range of marking. For stainless steel products, the largest utility spot diameter of 300mm, a minimum of about 100mm. Obviously, the lens focal length and maximize the range of marking can significantly shorten the laser engraving or laser engraving of the time.