A light bulb base is the part of a light bulb that connects it to the fixture or bulb socket. And a light bulb socket, also known as a light socket, lamp socket, bulb holder, or lamp holder, is a device that holds a light bulb and connects it to a power supply.
Light bulb bases and sockets are designed to hold the bulb securely and ensure electrical contact. Light bulb socket types and sizes vary based on lighting technology, applications, and power requirements.
Luckily, there are standards for light bulb base sizes in the lighting industry, and parts are made to meet those standards. To fit the bulb socket, light bulbs are made to fulfill these same specifications.
This article discusses the different types of light bulb bases and sockets. It broadly covers what the different light or lamp bases mean, why different lamp bases are used for different lighting applications, and where those light bulb bases are used. Additionally, it provides a light bulb base sizes chart and a light bulb socket sizes chart in shareable image format.
Light Bulb Base Sizes
Light bulb base sizes vary with the type of bulb and application. The base of a light bulb also contains information about the bulb type, and wattage, which may also indicate the maximum overall length of the bulb.
Light Bulb Base Sizes Chart
Here is a light bulb base chart that includes pictures of conventional light bulb bases, such as fluorescent bases, LED light bases, automotive light bulb bases, halogen bases, etc., to help you find the light bulb base you have in your hand or need for your light bulb socket.
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| Light Bulb Base Type | Bulb Base Name | Bulb Base Size |
|---|---|---|
| Screw Bases | E5 | 5 mm |
| E10 | 10 mm | |
| E11 | 11 mm | |
| E12 | 12 mm | |
| E14 | 14 mm | |
| E17 | 17 mm | |
| E26 | 26 mm | |
| E27 | 27 mm | |
| E29 | 29 mm | |
| E39 | 39 mm | |
| E40 | 40 mm | |
| Fluorescent Pin Bases | Miniature Bi-Pin | 15 mm |
| Medium Bi-Pin | 25-26 mm | |
| Single Pin | 25 mm | |
| Recessed Double Contact | 25 mm/38 mm | |
| 4-Pin | – | |
| Single-Ended, 4-Pin | – | |
| 2GX-13 | 68 mm | |
| Axial | – | |
| Twist and Lock Bases | GU10 | Pin Spacing 10 mm |
| GX8.5 | Pin Spacing 8.5 mm | |
| GX10 | Pin Spacing 10 mm | |
| GU24 | Pin Spacing 24 mm |
Light Bulb Sockets
It typically consists of an electrically wired base and a screw thread or other mechanism for holding the light bulb.
Light bulb sockets come in different sizes and shapes to fit different types of light bulbs and fixtures, such as incandescent, compact fluorescent, and LED bulbs. Light bulb socket sizes must match light bulb base sizes to fit properly.
Sockets make it easy and safe to change light bulbs or lamps (a process called “re-lamping”).
Light Bulb Socket Types
There are many different types of light bulb sockets, including:
- Edison screw: This is a standard light bulb socket that is commonly used in the United States and Europe. It has a base with a diameter of 10 mm to 39 mm and a screw thread for holding the light bulb.
- Bayonet mount: This is a light bulb socket that uses a bayonet mount to hold the light bulb. It has two pins on the base that connects to the electrical circuit and a pair of lugs that fit into slots on the light bulb.
- Candelabra: This is a small light bulb socket that is often used in chandeliers and other decorative fixtures. It has a base with a diameter of 12 mm and a screw thread for holding the light bulb.
- Intermediate: This is a light bulb socket that is intermediate in size between the Edison screw and the candelabra. It has a base with a diameter of 17 mm and a screw thread for holding the light bulb.
- Pin base: This is a light bulb socket that has two pins for connecting to the electrical circuit. It is often used in low-voltage lighting systems and in applications where space is limited.
- Bi-pin: This is a light bulb socket that has two pin-shaped prongs for connecting to the electrical circuit. It is often used in halogen and LED bulbs.
Why should you use the correct light bulb base for your fixture?
It’s important to use the right light bulb base for your fixture if you want your lights to work well and keep you safe. Different types of light bulb bases are designed to fit into specific types of fixtures and connect to the electrical wiring in different ways.
Using an incorrect light bulb base can lead to a number of problems, including:
- Safety hazards: If a light bulb base is not compatible with your fixture, it can become loose and pose a fire risk, or it may not make proper contact with the electrical wiring, which can result in an electrical shock.
- Poor performance: Using the wrong light bulb base can also cause your lights to be less bright, last less long, flicker, or do other things that aren’t good.
- Problems with compatibility: Some light bulb bases are made to work with certain types of dimmer switches or smart home systems. If you use the wrong kind of base, your lights might not work with these devices or might not work right.
Because of these things, you should always make sure to use the right light bulb base for your fixture. You can find this information in the owner’s manual for your fixture or by talking to a lighting pro. By using the right base, you can make sure your lights work right, last longer, and don’t put you or your home in danger.
How to choose the right light bulb base for your home or business?
There are a few things you should think about when choosing the right light bulb base for your home or business. This will help you choose the best base for your needs. These include:
Fixture Compatibility: When choosing a light bulb base, compatibility with your fixtures is the most important thing to consider. Each fixture has its own specifications, and you must choose a base that is compatible with the fixture in terms of size, shape, and electrical connections.
- Energy efficiency: Consider the energy efficiency of the bulb you want to use, as well as the base. LED bulbs are more energy-efficient than incandescent bulbs, for example, and choosing a base that is designed for LED bulbs can help to optimize energy efficiency further.
- Brightness: Consider the amount of light you need in a particular room or space, as well as the overall brightness of the bulb you want to use. Make sure that the base you choose can support the bulb’s brightness level and provide the amount of light you need.
- Compatibility with dimmer switches: If you want to use dimmer switches with your lights, make sure to choose a base that works with them. Some types of light bulb bases work better with dimmer switches than others, so look into your options before making a choice.
- Compatibility with smart home systems: If you have a smart home system, like a voice-activated assistant or an app on your phone, make sure you choose a base that works with your system. This will let you control your lights and use other smart home features from far away.
When choosing the right light bulb base for your home or business, you should think about a number of things, such as how well it works with your fixtures, how much energy it uses, how bright it is, how well it works with your dimmer switches, and how well it works with your smart home. By thinking about these things, you can make sure you choose the best base for your needs and get the most out of your lighting system.
Common misconceptions and mistakes when selecting light bulb bases
When choosing light bulb bases, it’s common to believe things that aren’t true or to make mistakes that can affect how well and safely your lighting system works. Here are some of the most common myths and mistakes that you should know about:
- Using the wrong size base: Using the wrong size base is one of the most common mistakes people make when choosing light bulb bases. This can lead to a bad fit, which can hurt the way your lights work and make them less safe.
- Assuming that all bases are identical: Another common mistake is thinking that all light bulb bases are identical. This isn’t true because different bases are made to work with different kinds of fixtures and bulbs.
- ignoring compatibility with dimmer switches: If you want to use dimmer switches with your lights, it’s important to choose a base that works with these devices. Some bases don’t work with dimmer switches, which can cause problems with how the light works or make it unsafe.
- Not considering smart home compatibility: If you have a smart home system, it is important to choose a base that is compatible with your system. This will let you use smart home features like controlling your home from afar and keeping track of how well it uses energy.
- Skipping the owner’s manual: It’s important to check the fixture’s owner’s manual before choosing a light bulb base. This manual will tell you which base to use and if there are any special things you need to know or do.
The impact of light bulb base compatibility on energy efficiency and performance
It’s important to be aware of common mistakes and misconceptions when choosing light bulb bases, like using the wrong size, thinking that all bases are interchangeable, ignoring dimmer switch compatibility, not thinking about smart home compatibility, and not reading the owner’s manual. By not doing these things, you can ensure your lighting system works well and is safe.
The way a light bulb base works with a fixture can have a big effect on how well it works and how much energy it uses. Here are some of the ways that using the correct light bulb base can affect energy efficiency and performance:
- Energy efficiency: If you use the wrong base for your light bulbs, they won’t work as well and will use more energy than they would if they had the right base. This can lead to higher energy bills and reduce the overall energy efficiency of your lighting system.
- Brightness: The right base for a light bulb can ensure that it fits securely in the fixture and makes good contact with the electrical wiring. This can help optimize the bulb’s brightness so that you get the maximum amount of light from your fixtures.
- Lifespan: The wrong base for a light bulb can put too much stress on it, shortening its life and making it need to be replaced more often. Using the right base can help your bulbs last longer and cost less to take care of.
- Performance with dimmer switches: Some types of light bulb bases are made to work with certain types of dimmer switches. If you use the wrong base, your lights might not work with these devices and might flicker, turn off, or do something else wrong.
The way a light bulb base works with a fixture can have a big effect on how well it works and how much energy it uses. By using the right light bulb base, you can help your lights work better, use less energy, and cost less to maintain.
How to convert between different types of light bulb bases?
Converting between different types of light bulb bases can be necessary if you want to use a different type of bulb in an existing fixture or if you want to use an existing fixture with a different type of bulb. Here are the steps you can follow to convert between different types of light bulb bases:
- Determine the type of base you currently have: Before you can convert to a different type of base, you need to determine the type of base you currently have. Look at the existing bulb and base, or consult the owner’s manual for your fixture.
- Choose the correct adapter: Once you know the type of base you currently have, you can choose the correct adapter to convert to the desired type of base. Adapters are available for many base types, including E26, E27, GU10, and others.
- Install the adapter: Installing an adapter is typically a straightforward process, but be sure to follow the instructions that come with the adapter carefully. Some adapters may require the use of screws or other hardware, while others may simply twist into place.
- Install the new bulb: Once the adapter is installed, you can install the new bulb into the base. Make sure to handle the bulb carefully and follow any manufacturer’s instructions regarding installation.
- Test the fixture: After installing the new bulb and adapter, it is important to test the fixture to ensure everything is working correctly. Turn on the lights and check for any issues, such as flickering or poor performance.
Converting between different types of light bulb bases is a straightforward process that can be accomplished with the right adapter. Just make sure you pick the right adapter, put it in carefully, and test the fixture afterward to make sure everything works as it should.
Socket Sizes Explained
Socket sizes are determined by a simpler rule known as Type-Size. The most common type of socket is the E type. The E stands for Edison and indicates that the socket is a screw type. The size is a simple millimeter measurement of the width. An E26 socket (the most common type) is 26 millimeters wide and features an Edison thread interior. Additionally, this socket is referred to as a Medium socket.
The three most often used sockets in the United States of America are the E12 (candelabra), the E26 (medium), and the E39 (mogul). As indicated in the table, there are several sockets that fall between these sizes. These three types of lighting are the most frequently used in traditional lighting.
Why do fittings have different bases?
Light bulbs have to fit snugly into light fixtures, so they are designed with different bases. The light bulb base has to match the socket in the light fixture. If light bulb bases were standardized, light bulbs could be interchangeable across many fixtures. However, light bulb bases are not standardized. This is to prevent dangerous light bulbs from being used in light fixtures that aren’t designed for them. Light fixture sockets have a grip on the inside of the socket, and light bulb bases have a matching metal tab on the outside of the base. A light bulb with no grip can be inserted into any kind of light fixture, but it won’t stay in place because the grip and tab don’t match up. This is why light bulb bases aren’t standardized: if they were interchangeable across light fixtures, people would risk inserting a light bulb into sockets that weren’t designed for them.
Light Bulb Base Types Explained
There are dozens of different light bulb bases. The most common is the Edison screw base, which may be found on most incandescent bulbs and many halogens, compact fluorescents, HIDs, and now LED lights.
Edison Screw Bases
The Edison screw (ES) is a type of light bulb socket that is universally used with electric light bulbs. Thomas Edison invented it and patented it in 1881.
The bulbs have metal bases (caps) that are threaded in the right direction and screwed into matching threaded sockets (lamp holders). In most cases, when bulbs are powered by alternating current, the thread is linked to neutral, and the contact on the bottom tip of the base is connected to the “live” phase.
In North America and continental Europe, Edison screws took the place of other types of sockets for general lighting. In the early days of electricity, the only standard connector was an Edison screw, and all appliances except light bulbs were hooked up to AC power through lamp sockets. Edison screw sockets are currently compliant with international standards.
The name “Exx” is made up of the letters “E” for “Edison” and “xx” for the millimeter diameter measured across the peaks of the thread on the base (male). For example, E12 has a diameter of 12 mm.
For mains supply lamps, there are four thread size groups that are typically used:
- Miniature Screw (E10)
- Miniature Candelabra (E11)
- Candelabra (E12)
- European (E14)
- Intermediate (E17)
- Medium (E26)
- Mogul (E39)
| Designation | Base major diameter (thread external) | Name | Application |
|---|---|---|---|
| E5 | 5 mm | Lilliput Edison Screw (LES) | Indicator lights, decorative lights |
| E10 | 10 mm | Miniature Edison Screw (MES) | Flashlights, bicycle lights |
E11 | 11 mm | Mini-Candelabra Edison Screw (mini-can) | 120 V halogen mini-candelabra |
| E12 | 12 mm | Candelabra Edison Screw (CES), C7 | 120 V candelabra/night lamp |
| E14 | 14 mm | Small Edison Screw (SES) | 230 V candelabra/chandelier, night lamps, and some pendant lights. |
| E17 | 17 mm | Intermediate Edison Screw (IES), C9 | 120 V appliance |
| E26 | 26 mm | Medium Edison Screw (ES or MES) Standard | 120 V lamps |
| E27 | 27 mm | [Medium] Edison Screw (ES) Standard | 230 V lamps |
| E29 | 29 mm | [Admedium] Edison Screw (ES) | |
| E39 | 39 mm | Single-contact (Mogul- in America) Goliath Edison Screw (GES) | 120 V 250+ W industrial |
| E40 | 40 mm | (Mogul) Goliath Edison Screw (GES) | 230 V 250+ W industrial |
E10 Base or Miniature Screw Base
In the lamp base designation “E-10” (sometimes called Miniature Edison Screw (MES), “E” stands for “Edison” and “10” indicates the diameter in millimeters as measured across the peaks of the thread on the base, e.g., E-10 base bulbs have a diameter of 10 mm. E-10 base light bulbs have a single contact on the bottom and are used in flashlights, indicators, and toys.
E11 Base or Miniature Candelabra Base
E11 (mini candelabra) is 11mm (0.433 in) in diameter and is a bit smaller than E12 (candelabra) which is 12mm in diameter. Its applications are very limited. E11’s are most commonly used for small, halogen (hot!) bulbs. Another most obvious application is obviously for 120-volt chandelier/candelabra. Low voltage models are used on Lionel toy trains and other toys. The E11 base is sometimes used for 50/75/100-watt halogen lamps in North America, where it is called the “mini-can”.
E12 Base or Candelabra Base
As the name suggests, the fitting is 12 millimeters in diameter size and is often deemed the Candelabra Edison Screw (CES). It is the home of C7-sized lamps, so if you bought a C7 lamp before, it utilized the E12 fitting.
Bulbs with E12 bases are commonly used for decorative applications, such as chandeliers, wall sconces, Christmas lights, restaurant pendant lights, ornamental lights, residential or commercial string lights, and night lights. Many bulbs with these bases are designed to mimic the look of a candle flame.
Common bulbs with E12 bases:
- Small tube-shaped bulbs: T8, T6, T22
- Candle-flame-shaped bulbs: C7, C9, CA10, B10
- Small globe-shaped bulbs: G14, G16, G50
E14 Base or European Base
European Or SES (Small Edison Screw) is a very common size used throughout Europe and the UK. An E14 bulb is one of the most-used bulbs in our homes found in many types of small light fittings around the home from bedside table lamps to wall lights and chandeliers . It is also called the bulb with the small screw socket. The bulb is called E14 because it refers to the socket: 14-millimeter diameter.
Common bulbs with E14 bases:
- A-shaped bulbs: A15
- Small tube-shaped bulbs: T8, T6, T22
- Candle-flame-shaped bulbs: C7, C9, CA10, B10
- Small globe-shaped bulbs: G14, G16, G50
- Marquee and sign bulbs: S11
E12 vs E14
| Criteria | E12 | E14 |
|---|---|---|
| Name | Candelabra Edison Screw (CES), C7 | Small Edison Screw (SES) |
| Size | 12 mm | 14 mm |
| Application | 120 V candelabra/night lamp | 230 V candelabra/chandelier, night lamps, and some pendant lights. |
E17 Base or Intermediate Edison Screw Base
Intermediate Screw Base (E17) Bulbs are sometimes called Intermediate Edison Screw (IES), “E” stands for “Edison” and “17” indicates the diameter in millimeters as measured across the peaks of the thread on the base
Like candelabra bulbs with E12 bases, bulbs with E17 bases are used for decorative applications, such as chandeliers, wall sconces, Christmas lights, restaurant pendant lights, ornamental lights, and sign or marquee lights. Bulbs with these bases are commonly used for appliance lights, such as microwave lights, refrigerator lights, and range hood lights. They’re also found in ceiling fan light fixtures.
Common bulbs with E17 bases:
- A-shaped bulbs: A15
- Small tube-shaped bulbs: T8, T6, T22
- Candle-flame-shaped bulbs: C7, C9, CA10, B10
- Small globe-shaped bulbs: G14, G16, G50
- Marquee and sign bulbs: S11
E26 Base or Medium Edison Screw (MES) Base
E26 is the size of most light bulbs used in the U.S. It’s referred to as having a “medium” or “standard” base.
The letter “E” in E26 refers to Edison Screw, the most standard of lamp bases, while the numerical “26” refers to its diameter in millimeters (approximately 1 inch).
E26 is also commonly referred to as a Medium Edison Screw (MES).
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 vanity lights.
Common bulbs with E26/E27 bases:
- A-shaped bulbs: A19, A15, A21
- Globe-shaped bulbs: G30, G25, G16.5
- PAR (parabolic aluminized reflector) spotlight and floodlight bulbs: PAR16, PAR20, PAR30, PAR38
- BR (bulged reflector) spotlight and floodlight bulbs: BR20, BR30, BR40
E39 Base or Mogul Base
E39 is known as the large base or mogul base. Its typically what is used on older metal halides and high pressure sodium from 100 watts and up. The E is for Edison screw base and the 39 is 39 mm across. Larger than the standard E26 or 26 mm across.
The large E39 “mogul” base is used on street lights, and high-wattage lamps (such as a 100/200/300 Watt three-way). Chances are you won’t have a need for these guys.
Common bulbs with E39/E40 bases:
- PAR (parabolic aluminized reflector) bulbs: PAR20, PAR38, PAR40
- Blown tubular bulbs: BT37, BT56
- Elliptical dome bulbs: ED17, ED28, ED37
FLUORESCENT PIN BASES
- Miniature Bi-Pin
- Medium Bi-Pin
- Single Pin
- Recessed Double Contact
- 4-Pin
- Single-Ended, 4-Pin
- 2GX-13
- Axial
| Base | Socket Type | Spacing | Application | |
|---|---|---|---|---|
| Miniature Bi-Pin | G5 Bi-Pin base | 5 mm | T4/T5 / T16 Tubelights | |
| Medium Bi-Pin | G13 base | 13 mm | T8 / T26 Tubelights | |
| Recessed double contact | R17d base | 17mm | T17 / PG17 | |
| 4-Pin | G10 quad pin | T9 /T10/ T29 | ||
| Single pin | Fa6, Fa8 | 6 mm, 8 mm | Less common |
Miniature Bi-Pin
Miniature BiPin, also called mini-BiPin, sockets have pins placed closer together. Not only are they smaller in size, but they’re also used in a smaller type of light too.
The miniature bi-pin sockets are used in linear fluorescent lighting, like T5 lights.
Medium Bi-Pin
When you’re wondering what the difference between a medium and a miniature bi-pin socket is, it doesn’t just involve the size of the part itself. The actual socket is what helps to generate the correct amount of electricity to the light. If the bi-pin is too small or large for the light, it could cause a significant electrical problem.
Medium bi-pin sockets are generally used in a variety of linear fluorescent bulbs, like the T8 and T10 lights.
Single Pin
Some linear fluorescents have a single pin Fa8, but they are not very common.
Recessed Double Contact
Some linear fluorescents have double contact R17d, but they are not very common.
TWIST & LOCK BASES
- GU10
- GX10
- GU24
BI PIN BASES
A bipin or bi-pin (sometimes referred to as two-pin, bipin cap or bipin socket) is a type of lamp fitting. They are included in the IEC standard “IEC 60061 Lamp caps and holders together with gauges for the control of interchangeability and safety”. They are used on many small incandescent light bulbs (especially halogen lamps), and for starters on some types of fluorescent lights.
The bi-pin base was invented by Reginald Fessenden for the 1893 World’s Fair in Chicago.
- G4 (smallest light bulb base)
- GU4
- GZ4
- G5.3
- G5
- GU5.3
- GX5.3
- GY5.3
- G6.35
- GY6.35
- GZ6.35
- GY8
- G8.5
- G9
- G9 Pin Blade
- G9.5
- GX9.5
- GZ9.5
- G12
BAYONET BASES
Bayonet bases are a type of electrical connector that uses a bayonet-style locking mechanism to secure the connection. They are commonly used in various applications, such as lighting, electrical power distribution, and telecommunications.
The bayonet base consists of a base and a mating pin, which are designed to fit together in a specific way. The base has two or more protruding tabs that fit into corresponding slots in the pin, and the pin is then rotated to lock the connection in place. This design allows the connection to be made and broken quickly and easily, while also providing a secure connection.
There are several different types of bayonet bases:
- Miniature Bayonet
- Double Contact Bayonet (BA15d)
- Single Contact Bayonet (BA15s)
- D. C. Bayonet, Medium (BY22D)
- Index Double Contact Bayonet
Each type has a specific number of pins and is designed to fit a particular type of lamp or device. For example, a bi-pin base is commonly used for halogen and LED lamps, while a double contact base is used for fluorescent lamps.
WEDGE BASES
Wedge bases are a type of electrical connector that are commonly used in automotive lighting and other applications. They consist of a base and a mating pin, which are designed to fit together in a specific way. The base has a wedge-shaped groove that fits over a corresponding protrusion on the pin, and the pin is then pushed into the base to lock the connection in place.
Wedge bases are designed to be easy to use and provide a secure connection. They can be found in a variety of sizes and configurations, depending on the specific application.
- Wedge
- Wedge D.F.
- Wedge S.F.
- RX7s
- Slide
- Wedge Subminiature
For example, a T10 wedge base is commonly used in automotive taillights, while a T15 wedge base is used in some turn signal and brake light applications.
In addition to automotive lighting, wedge bases are also used in other applications such as outdoor lighting, commercial lighting, and theatrical lighting. They are a popular choice because of their simplicity, reliability, and versatility.
COMPACT FLUORESCENT PLUG IN BASES
- 2G7
- 2GX-7
- 2G11
- G23
- G24d-2
- G24d-3
- G24q-1
- G24q-2
- G24q-3
- GX23
- GX23-2
- GX24q-1
- GX24q-2
- GX24q-3
- GX24q-4
- GX24q-5
MINIATURE & AUTOMOTIVE BASES
- Prefocus
- Right Angle Prefocus
- Axial Prefocus
- Straight
- Midget Flanged Single Contact
- Miniature Flanged Single Contact
- Miniature Single Contact
- P15S
- P28S
- P32d2
- P43T
- P43T-38
- PK22s
- PX26d
SPECIALTY BASES
- G53
- Festoon
- 2 Contact Lugs
- 3 Contact Lugs
- Screw Terminal (Multi-Purpose)
- Mogul End Prong (GX16d)
- Metal Clip
- Rigid Loop
- Side Prong
- Lead wires
- S14s
CABLE BASES
- MALE FLAT
- FEMALE FLAT
- PK30d
MISCELLANEOUS BASES
- GU6.5
How do you choose the right light bulb socket?
When choosing a light bulb socket, consider the following factors:
- Type of light bulb: Make sure the socket is compatible with the type of light bulb you want to use. Different sockets are designed for different types of bulbs, such as incandescent, fluorescent, or LED.
- Voltage rating: The socket should be rated for the voltage of your electrical circuit. For example, a 120V socket should not be used on a 240V circuit.
- Wattage rating: The socket should be rated for the wattage of the light bulb. A higher-wattage bulb will generate more heat and may require a socket with a higher wattage rating.
- Size: The socket should be the right size for the light bulb and the fixture it will be used in. Measure the base of the bulb and the diameter of the fixture’s opening to ensure a proper fit.
- Base type: The socket should have the right type of base for the light bulb. For example, an Edison screw socket is required for a bulb with an E26 base, while a bayonet mount socket is required for a bulb with a B22 base.
Automotive light bulb Socket types
Automotive light bulbs typically have one of the following socket types:
- Bayonet base: This is a light bulb socket that uses a bayonet mount to hold the light bulb. It has two pins on the base that connect to the electrical circuit and a pair of lugs that fit into slots on the light bulb.
- Wedge base: This is a light bulb socket that has a flat, wedge-shaped base that fits into a corresponding slot in the light fixture. It is often used in tail lights, brake lights, and turn signals.
- H4 base: This is a light bulb socket that has a rectangular base with four pins arranged in a square pattern. It is often used in headlights and fog lights.
- H7 base: This is a light bulb socket that has a rectangular base with two pins arranged in a straight line. It is often used in headlights and fog lights.
- P13W base: This is a light bulb socket that has a rectangular base with four pins arranged in a rectangle pattern. It is often used in daytime running lights and fog lights.
12 Volt light bulb Socket types
There are several types of 12 Volt light bulb sockets that are commonly used in automotive and marine applications, including:
- Bayonet base: This is a light bulb socket that uses a bayonet mount to hold the light bulb. It has two pins on the base that connect to the electrical circuit and a pair of lugs that fit into slots on the light bulb.
- Wedge base: This is a light bulb socket that has a flat, wedge-shaped base that fits into a corresponding slot in the light fixture. It is often used in tail lights, brake lights, and turn signals.
- H4 base: This is a light bulb socket that has a rectangular base with four pins arranged in a square pattern. It is often used in headlights and fog lights.
- H7 base: This is a light bulb socket that has a rectangular base with two pins arranged in a straight line. It is often used in headlights and fog lights.
- P13W base: This is a light bulb socket that has a rectangular base with four pins arranged in a rectangle pattern. It is often used in daytime running lights and fog lights.
- 1157 base: This is a light bulb socket that has a rectangular base with two pins arranged in a straight line. It is often used in brake lights and turn signals.
Light Bulb Socket with Switch
A light bulb socket with a switch is a device that allows you to turn the light bulb on and off without having to physically unplug it or flip a switch on the wall. It typically consists of a base that is wired to the electrical circuit, a screw thread or other mechanism for holding the light bulb, and an inline switch that can be used to turn the light on and off. There are many different types of light bulb sockets with switches, including those for incandescent bulbs, compact fluorescent bulbs, and LED bulbs. They can be used in various applications, such as lamps, overhead lighting, and outdoor lighting.
How do I know what base my light bulb is?
The light bulb base is usually indicated by a series of numbers that look like E-26, B22d or E-27. These markings are found on the outside of light bulbs and indicate what type they are. For example, this marking indicates an Edison screw light bulb: E-26. This marking means that Edison screw base is used. The number 26 indicates the diameter of the light bulb base in millimeters – so you can see this would fit into a standard E26 socket.
Which light bulb base types are interchangeable?
The screw-in bases, Edison E26 and the larger-sized E27 are usually interchangeable. The medium-sized B22d is also often used with a bayonet fitting.
The smaller S14s size may not be compatible with all fixtures because of its small diameter which can prevent it from being screwed into the light fixture socket. E11 and E12 are not interchangeable because of their different size.
Does the Bulbs Base affect voltage and performance?
The light bulb base affects the voltage and wattage that can be used on a light fixture. In North America, there are three different types of electrical outlets: A-type, B-Type, and C-Type sockets. The type of socket dictates how much power you can safely put through it without overloading or shorting out your home’s wiring.
You can put more power through a B-type socket than an A-type one, and you can put even more power through a C-Type socket than a B type – but for this reason, it is recommended to not use light bulbs with higher wattage in your home’s fixtures unless they are specifically designed for that voltage or higher. You should always check your light fixture’s label to see what type of voltage and wattage it will support.
When you buy light bulbs for a home with C-type outlets, make sure they can handle the higher operating voltages – otherwise, you risk having them blow out or catch fire if used in such fixtures. If these safety risks don’t concern you, then by all means go for it – but be sure to read the fine print on the light bulb packaging.
Which is the largest light bulb base?
The biggest light bulb base is one with a diameter between 40mm and 50 mm (E39 or E40).
Which is the smallest light bulb base?
The smallest light bulb base is G4 with a diameter of 4 mm.
Final Verdict on Light bulb base sizes
In this article, we tried to discuss different light bulb base types. There are many different types of light bulb bases, each of which is designed to fit a specific type of socket or fixture. It is important to choose the right type of light bulb base for your specific application, as using the wrong base can cause problems such as flickering or improper electrical connections.