Fluorescent Light Bulb Base Types

The t stands for tubular and the numbers are an index for the diameter in inches of the tube.

Fluorescent light bulb base types.

These photos show the different types of connectors pins or bulb bases for various fluorescent lamps. Rapid start lamps are the most popular fluorescent lamp type used in commercial applications such as office buildings. Rapid start 40 watts or less and preheat lamps. Pin type bases are normally used for track lighting landscape bulbs.

T4 t5 t8 and t12. Frequently fluorescent bulbs will have either a single pin or bi pin two pin base type. For alaska hawaii the base rate is 27 59 and surcharges may apply for larger orders. Photo guide to fluorescent bulbs by connector base.

Most common light bulb uses including lamps recessed flush mount flood lights are going to have one of the first three base types shown above. Below is a range of fluorescent lamps one for each popular starting method. The most common that we see is a fluorescent bent t8 with six inch leg spacing. So in most cases you won t have to physically measure the tube s diameter and length.

For shipments to canada you can add some items to your cart to determine the shipping rate. Fixtures with rapid start programmed start and dimming ballasts use non shunted lamp holders. Look at your fixture to determine its base type. Some will have a recessed double contact.

As you would expect the tube is bent in a u shape. Most tube lighting will have its size mentioned on an end of the tube. For this reason they could also be called u bent fluorescents. The illustrations are not to scale.

There are 4 different fluorescent light options. By eliminating bulbs that don t match your base type you are on the right track to finding the right type of fluorescent light bulb. Find the light bulb base type you re looking for with this visual chart detailed illustrations of general bases fluorescent bases and specialty halogen base types. Fixtures with instant start ballasts require shunted lamp holders.

The type of fluorescent socket needed depends on the type of ballast used in the fixture. Rapid programmed start traditional straight fluorescent bulbs use a turn type connector whose internal metal clips contact two pins at each end of the bulb. This is to cover all of the additional shipping materials that are needed to ensure a safe. Certain longer fluorescent led tubes will be assessed a shipping surcharge.

For bulb dimensions see the table above starting at fluorescent light bulb codes types click to enlarge any image. Medium standard base code. The electrical industry refers to these as bi pin bulbs and bi pin sockets. Also what is the shape of your bulb.