Chrome barrel plating is an electrolytic plating method that efficiently processes a large quantity of small parts. By rotating the parts within a dedicated barrel tank, immersing them in the plating solution, and applying electricity, uniform plating thickness and excellent mass productivity are achieved through the contact and agitation among the parts. Because it can impart high hardness, corrosion resistance, and a beautiful appearance characteristic of chrome plating, it is widely used for fasteners such as screws, bolts, and nuts, terminals of electronic components, and small mechanical parts. From the perspective of environmental regulations, the adoption of trivalent chrome barrel plating has been advancing in recent years, replacing hexavalent chromium. This technology is an indispensable processing method for achieving both functionality and cost performance.