What is Small Edison Screw​? E10

With 15 years of rich manufacturing expertise, our LED bulb manufacturer guides you through the ultimate guide to small edison screw and other light bulb base types. Discover the different bulb caps and their applications with seasoned experts.

Have you ever bought a replacement light bulb, only to find it’s too small or too big for your lamp socket? You aren't alone. Understanding light bulb bases is key to avoiding frustration.

One of the most common confusing terms in lighting is the "Small Edison Screw," often abbreviated as SES.

As leaders in lighting information, we have put together this quick guide to explain exactly what an SES base is, the different types available, and how to ensure you buy the right one every time.

Understanding the "Edison Screw" System

Before defining the "small" version, we must understand the system. The "Edison Screw" is the standard screw-in light bulb base used globally, named after inventor Thomas Edison.

In the industry, these bases are identified by the letter "E" followed by a number.

• "E" stands for Edison.

• The Number refers to the outer diameter of the screw thread in millimeters (mm).

Therefore, a standard household bulb in the US is an E26 (26mm), while in Europe, it is an E27 (27mm).

What is a Small Edison Screw (SES)?

A Small Edison Screw refers to bases that are smaller than the standard household size, typically used for decorative lighting, chandeliers, desk lamps, and appliance bulbs (like fridge or oven lights).

However, "Small Edison Screw" can mean different things depending on where you live.

1. The True SES: The E14 Base (Most Common Globally)

In most of the world (including Europe, the UK, Asia, and Australia—regions with 220-240V power), the term "Small Edison Screw" or "SES" specifically refers to the E14 base.

Specifications of E14:

• Thread Diameter: 14mm across the widest part of the screw base.

• Common Uses: Chandelier candles, golf ball shape bulbs, small table lamps, and refrigerator bulbs.

2. The North American Equivalent: The E12 Base (Candelabra)

In North America (US and Canada—regions with 120V power), the E14 is rare. Instead, the common small base is the E12, often called the "Candelabra Edison Screw" (CES). While technically a CES, many consumers loosely refer to it just as a "small screw base."

Specifications of E12:

• Thread Diameter: 12mm across the widest part of the screw base.

• Common Uses: Chandeliers, night lights, and decorative holiday lighting in North America.

  
  

3. The Japan Equivalent: The E11 Base and E17 Intermediate

Japan has its own set of standards that differ from both Europe and North America.

• E11 Base (Mini-Candelabra): With a 11mm thread diameter, this is slightly smaller than the North American E12. It's often used in halogen lamps and some specialized LED fixtures in Japan.

• E17 Base (Intermediate): With a 17mm thread diameter, this falls between the "small" sizes and standard sizes. It's a very common size in Japan for desk lamps, small ceiling lights, and appliances.

4.  E5 and E10 Miniature Lamp

Also referred to as MES (Miniature Edison Screw), these are commonly found in old chandeliers, so bulbs designed to fit E10 lamp holders tend to be more decorative in appearance to suit the light fitting. You will also find bulbs with E10 caps in miniature lamp applications and indicating panels.

Because E11, E12, and E14 are all so close in size, it is easy to mix them up. Using the wrong base can result in a poor electrical connection or a bulb that won't fit at all.

Here is how to select the right one:

1. Check the Old Bulb: Look at the metal base or the glass of your old bulb. The code (E11, E12, E14, or E17) is often printed there.

2. Check the Light Fixture: Look at the socket itself or a label on the lamp; it usually specifies the required base type and maximum wattage.

3. Know Your Region:

• USA/Canada: You most likely need an E12.

• UK/Europe/Australia: You most likely need an E14.

• Japan: You may need an E11, E12 or E17.

  Measure It: If you are unsure, use a ruler or calipers to measure the diameter of the old bulb's metal base base across the threads.

  
  

• Screw Cap Name	Diameter in Millimeters
  E5	4.6MM
  E10	9.3MM
  E11	10.5MM
  E12	11.5MM
  E12S	12.5MM
  E14	13.5MM
  E14S	14.5MM
  E17	16.5MM
  E27	26MM

• If you are still unsure about which base to choose, please contact our professional lighting engineers.