What is Medium Base Bulb

Horace He

Last Updated: August 1, 2023

What is Medium Base Bulb

A medium base bulb, also known as an E26 socket, is a standard light bulb commonly used in residential settings. It is characterized by its threaded brass base, which is referred to as the medium base. This type of base is the most widely used and commonly found in lamps and fixtures. The medium base bulb is typically found on A19, A15, and A21 lamps, which are commonly used in table lamps and residential ceiling fixtures. It is important to note that the medium base is the most common type of base used on both incandescent and LED lamps.

Compared to other types of bases used in lighting, such as the intermediate base, candelabra base, mini-candelabra base, and mogul base, the medium base is larger than the intermediate base, candelabra base, and mini-candelabra base, but smaller than the rarer mogul base. However, adaptors are available to fit a smaller base into a larger socket, allowing for flexibility in lighting options. It is worth mentioning that the names of the sockets correspond to the names of the bases.

Frequently Asked Questions

What Are the Two Types of Bulb Bases

Normally, a bulb typically has either a screw base or a bayonet base. The diameter of the base is usually measured for bulbs with a screw base, while the spacing between two pins is measured for bulbs with a pin base.

How Do I Know if My Bulb Is A19

An A19 bulb is characterized by its classic light bulb shape, often described as resembling an upside-down pear. The “19” in A19 refers to the bulb’s diameter at its widest point, which is measured in eighths of an inch. Therefore, an A19 bulb has a diameter of approximately 2.4 inches, calculated by dividing 19 by 8 inches.

Is A19 a Medium Base Bulb

Medium base (E-26) | A19 | General Purpose LED Light Bulbs are the type of bulbs that are considered to have a medium base.

What Is the Difference Between A19 and A21 vs A23

The digits that come after the letter indicate the outer diameter of the light bulb at its widest point, measured in eighths of an inch. To illustrate, an A19 has a diameter of 2 3/8 inches, an A21 has a diameter of 2 5/8 inches, and an A23 has a diameter of 2 7/8 inches.

Can I Use A21 Bulb Instead of A19

Except for the longer neck and larger bulb, the A21 light bulbs have a nearly identical appearance to the A19 version. They are similar enough in size that they can be used interchangeably in the same fixtures or for similar lighting purposes.

What Do the Letters on Light Bulbs Mean

The letters on light bulbs serve as an indication of the bulb’s shape, while the numbers correspond to the bulb’s diameter measured in eighths of an inch. For instance, the widely used A-19 bulb is of “A” type and has a diameter of 23/8″. Another example is the 65BR40 bulb, which is a reflector bulb with a wattage of 65 and a diameter of 5 inches.

Is E26 Medium Base Same as A19

Yes, E26 medium base and A19 are interchangeable. The only distinction between the two is their size and shape. A19 light bulbs have an E26 base and can be used in sockets designed for Edison bulbs.

Are A19 and A21 Bulbs Interchangeable

Yes, A19 lamps can be used in A21 lampholders. This is because A19 lamps are smaller in size compared to A21 lamps, allowing them to fit into most fixtures and lampholders designed for A21 lamps. Additionally, since both A19 and A21 lamps utilize the same E26 base, the A19 lamps will fit perfectly into the socket.

Is E12 a Medium Base Bulb

Small Base Light Bulb

The E12 designation refers to the diameter of the screw base in millimeters, indicating that an E12 light bulb has an Edison Screw base that measures 12 millimeters in diameter. This straightforward naming convention makes it easy to remember the size of this particular base.

What Is the Difference Between an A15 and A19 Light Bulb

The A15 light bulbs are smaller in size compared to the A19 light bulbs. Both types of bulbs can be used in a standard household medium base (E26 base). However, it is important to ensure proper ventilation in the surrounding area to avoid any potential fire hazards.