No.  Part Name                Material         Electroplated

1     Tube                          Iron                 Nickel Plated

2     Casing                        Iron                 Color Plated

3     Temp. Mom.              Alloy                    - - -

4      Porcelain Socket       Ceramics             - - -

5      Insulator                   Barelite                - - -

6      (-) Terminal               Iron                 Color Plated