What Are Light Bulb Mounts?

January 30, 2014
What Are Light Bulb Mounts?

Who would have thought that choosing a light bulb could have so many options?

From the light fixture, to the globe technology to the light globe mount, there are many aspects which need consideration.

When researching your lighting, you may come across B22 or SES14; but what do these numbers and letters actually mean?

They describe the Light Bulb Mount; the way the light globe will fit your light fixture. Here’s simple explanations that will help you choose the right light globe and mount for your light.

What is an ES, SES Bulb?

An ES or SES screw base is the Thomas Edison screw fitting system of screw mounts. Fitting to its name, the bulb has a threaded metal base which screws into a matching socket. The bulb must be closed tightly as the threaded metal base completes the circuit for the light to activate.

The E denotes that the type of bulb in an Edison Screw and the following number indicates the diameter of the base in millimetres.

In Australia the most common Edison Screw Bulb sizes are E14 and E27; the 14mm and 27mm.

However, there are many other options available:

Globe Name - Base Diameter (mm):

  • E5 - 5mm
  • E10 - 10mm
  • E11- 11mm
  • E12 - 12mm
  • E14 - 12mm
  • E17 - 17mm
  • E26 - 26mm
  • E27 - 27mm
  • E29 - 29mm
  • E39 - 39mm
  • E40 - 40mm

Edison Screw Light Bulb

What is a Bayonet Mount?

The Bayonet light bulb mount generates light by connecting the male cylindrical side with a radial pin to a female receptor with matching L-shaped slots to keep the two parts together. The B denotes that the type of bulb is a Bayonet Base mount, the following number indicates the diameter of the base in millimetres and the small letters following the number indicated whether it has single or double contacts. If a Bayonet Base mount code includes a G, this indicates that the product is bi-pin. The most commonly used Bayonet Base mount in Australia is the B22; a 22mm base, for a smaller option the B15; a 15mm base, is often used.

Bayonet Mount Bulb

Both the Edison Screw and Bayonet Mount use all types of lighting technology: LED, Fluorescent, Incandescent and Halogen. Many light fixtures are available in both a screw in and bayonet mount option, but be sure to double check your light fixture when purchasing your light globes.