What are Light Bulb Base Types

The base of a light bulb is what actually screws or plugs into your socket or fixture. Bases are mostly made of aluminum or brass.

There are lots of base types. I want to review some of the more common bases you'll have. A large majority of light bulbs that have screw in bases will have medium size bases. This is what you see on most of your standard bulbs as well as flood lights. Another common screw in base is a candelabra base which you see most often on bulbs that go in smaller table lamps, chandeliers and sconces. A much larger base type that screws in is a mogul base and is most often found on metal halide or high pressure solium light bulbs.

Now if you have a light bulb with a base that sticks in and twists to connect to the power current, these are called double contact bayonet and single contact bayonet bases.

Another base that is becoming common is a plug in base. Codes for these are PL-L, PL-C, PL-S and PL-T. Plug in bases are on compact fluorescent light bulbs and are becoming more and more popular. They simply plug in to the socket.

Lots of specialty light bulbs have different kind of bases and we plan to address them one at a time through out our blog.

Holly Eddins