Types of Lighting Sockets and Light Bulb Bases
Naming Conventions
Bases of light bulbs are normally defined by a letter-number-letter format, with the last letter optional. The first letter designates the shape or form of the base, the numbers represent either the width of the base or the distance between the pins. The numbers are normally in millimeters. The second letter designates the number of pins or contacts on the lamp.
Lamp Base Shape Type
- B Bayonet Collar
- E Edison Screw
- F Single Pin Type
- G Multiple Pin Type
- K Cable Connections
- P Pre-focussed
- R Recessed Contact(s)
- S Shell-type
- T Telephone Slide
- W Wedge Base
- X Special Type
Lamp Number of Pin or Contacts
- s Single
- d Double
- t Triple
- q Quadruple
