Incandescent Lamps

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 wound into a helical coil or it may be deeply fluted; CC (coiled coil) - wire is wound 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	2CC-6

C-7A	C-8 CC-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

Back to the Top Base Types (Not Actual Sizes)

Medium	3 Contact Medium	Medium Skirted	Mogul

3 Contact Mogul	Mogul Prefocus	S-14s Philinea	Miniature Candelabra

Candelabra	Candelabra Bayonet Single or Double Contact	Candelabra Prefocus	Intermediate

Recessed Single Contact	Metal Sleeve Flexible Lead	Medium Side Prong	Insul End Prong or Mogul End Prong

Multipurpose

Back to the Top Bulb Shapes (Not Actual size) The size and shape of a bulb is designated by a letter or letters followed by a number. The letter indicates the shape of the bulb while the number indicates the diameter of the bulb in eighths of an inch. For example, "T-10" indicates a tabular shaped bulb having a diameter of 10/8 or 1 1/4 inches. The following illustrations show some of the more popular bulb shapes and sizes.

A-19	A-21	A-23	B-10 1/2

B-13	BA-9	BA-91/2	BR-19

BR-30	BR-40	C-7	ER-30

F-10	F-15	F-20	G-161/2

G-25	G-40	K-19	P-25

PAR-16	PAR-20	PAR-30S	PAR-30L

PAR-36	PAR-38 DiOptic Reflector	PAR-38	PAR-64

PAR-64	PS-35	PS-52	R-20

R-40	RP-11	S-6	S-11

S-14	T-41/2	T-5	T-6

T-8	T-8	T-10

Filament Designations