Incandescent

Incandescent Filament Designations

Filament designations consist of a letter or letters to indicate how the wire is coiled, and an arbitrary number sometimes followed by a letter to indicate the arrangement of the filament on the supports. Prefix letters include C (coil) — Wire is would into a helical coil or may be deeply fluted; CC (coiled coil) — wire is would into a helical coil and this coiled wire again wound into a helical coil. some of the more commonly used types of filament arrangements are illustrated.

C-2V
CC-2V
C-5 C-6
CC-6
CC-6 C-7A C-8
2CC-8 C-9 C-11
CC-11
C-13
CC-13
C-17A C-2R
CC-2R
MP BP FF M SC CC-6
CC-8