What is Edison Screw

What is Edison Screw

Edison screw is bulb base design named after Thomas Alva Edison, the renowned American inventor who played a significant role in the development of the incandescent light bulb. An Edison Screw fitting consists of a socket with a center contact and a female screw receptacle, along with a bulb that has a male screw pattern on one end. This design allows for easy installation and removal of the bulb by simply screwing it into the socket.

Edison Screws come in various sizes, with each size identified by the letter “E” followed by the diameter of the base in millimeters. For example, the most common household bulb in the United States is the E26, which has a base diameter of 26mm (approximately 1.02 inches). In Europe and other regions with 240v electricity, the E27 is more commonly used.

In addition to the E26 and E27 sizes, smaller sizes like E11 and E12 are typically used for candelabra bulbs, while intermediate sizes like E17 and E14 are also available. The larger sizes, such as E39 and E40, are known as goliath or mogul bulbs. Bulbs with Edison Screw bases smaller than E11 or larger than E40 are less common and have specialized uses. These sizes are typically used with 120v or 240v electricity.