Standard Light Bulb Base Size

There are four commonly used thread size groups for lamps.

Standard light bulb base size.

The candelabra e12 has a diameter of 12 millimeters. The number that follows the a designation indicates the nominal major diameter of the bulb either in one eighth. They are commonly used for general lighting in standard light fixtures such as ceiling lights lamps can lights outdoor spotlight and flood light fixtures and. Unlike the light bulb shapes the number in the light bulb base measures the light bulb base diameter in millimeters.

It s used for nightlight bulbs and sometimes for decorative light bulbs used in chandeliers and over bathroom mirrors. 1 888 455 2800 fax 1 508 363 2900. The first letter designates the shape or form of the base and the number represents the width of the base normally in millimeters. Bulbs with these bases are the most popular of all screw base bulbs.

Bulbs with these base types can be used interchangeably as there is only a 1 millimeter difference in base size. The a series light bulb is the classic glass light bulb shape that has been the most commonly used type for general lighting service gls applications since the early 20th century. A19 led filament bulbs in ceiling fan fixture a21 led bulbs in bedroom lamps a19 gold tint led filament bulb in porch light fixture a19 led fireworks bulbs in string lights. E17 intermediate base is in between these two sizes.

E26 mes in north america e27 es in europe mogul. Standard arbitrary a bulbs are the most widely used and thought of when it comes to household lighting. It s referred to as having a medium or standard base. A further explanation of the light bulb base sizes you can look at the letter number references e12 e17 and e26 to help understand a bulbs base style and size.

This base was developed by thomas edison for the first light bulbs and is still in use today. From top left to bottom right. Screw bases come in several sizes and they are referred to by both a descriptive name and size. E12 is the smaller candelabra base.

E12 north america e11 in europe intermediate. Fluorescent pin bases miniature bipin medium bipin single pin recessed double contact 4 pin single ended 4 pin 2gx 13 axial twist lock bases 10mm gu10 10mm gx10 24mm gu24 bi pin bases 4mm g4 4mm gu4 4mm gz4 5 3mm g5 3 5mm g5 5 3mm gu5 3 5 3mm gx5 3 5 3mm gy5 3 6 35mm g6 35 6 35mm gy6 35 6 35mm gz6 35 8mm gy8 8 5mm g8 5 9mm g9 9mm g9 pin.