Edison screw (ES) mount

Edison screw (ES) mount 
This mount type is easily recognisable and very common.

Developed by Thomas Edison and licensed by Mazda in 1909, the Edison screw (ES) light bulb base is one of the two most common light fittings in Australia (the other is the bayonet cap).

Most ES mounts are installed by twisting the bulb clockwise into the fixture. The fitting must be closed tightly because, unlike bayonet cap bases, the screw actually completes the circuit for the light to activate. If it’s not screwed in tight enough, it will not work and could present an electric shock hazard.


How to identify Edison screw (ES) sizes

Similar to bayonet caps, the fixtures come in various sizes. To find the right size, look for the letter E followed by two numbers. These numbers refer to the base’s diameter in millimetres.

The must common size ES bases in Australia and E27 and E14, which are 27mm and 14mm respectively.