Copper in color and matte to a very shiny finish. Good corrosion resistance when used as an undercoat. A number of copper processes are available - each designed for a specific purpose.
- Brightness (to eliminate the need for buffing).
- High speed (for electroforming).
- Fine grain (to prevent case hardening), etc. All steel parts having a hardness of Rockwell C35 and higher shall be baked at 191°± 14°C (375° ± 25°) for 24 hours within four (4) hours after plating to provide hydrogen embrittlement relief. Plated springs and other parts subject to flexure shall not be flexed prior to baking operations.
Class 0: (Unless otherwise specified .001-.005") For heat treatment stop-off.
Class 1: (.001" minimum thickness) For carburizing and decarburizing shield, also plated through printed circuit boards.
Class 2: (.0005" minimum thickness) As an undercoat for nickel and other plating.
Class 3: (.0002" minimum thickness) To prevent basis metal migration into tin (prevents poisoning of solidarity).
Class 4: (.0001" minimum thickness).