Profile: Metro Engineering and Plating Works Ltd. specializes in offering aluminum treatment services. Our services include sulphuric acid anodizing, chromic acid anodizing, hard anodizing, semi-hard anodizing, dual finishing, and titanium finishing services. The semi-hard anodizing process was devised to satisfy the requirements for a hard surface finish combined with good color options. Semi-hard anodizing provides increased hardness, good adhesion, electrical insulation, heat resistance, and increased corrosion resistance. Semi-hard anodizing will usually result in a slightly lower surface finish to that of the original component, but can be more easily dyed than the full hard anodized finish, giving a greater range of available colors.