See this extra contact?
an on / off socket at the lamp repair shop in south portland, maine.
a three way socket at the lamp repair shop in south portland, maine
arrow identifying a three way socket contact at the lamp repair shop in south portland, maine.
There is an easy way to know if you have a three-way or an on/off socket.
If your socket has that extra contact, it is a three-way socket, and a three way socket really needs to use a three-way light bulb. Using a non three-way causes flickering and shortens the life of your socket and bulb.
Note: Do not confuse a three-way socket with a three termnal socket. They are not the same thing at all. A three-way socket has three illumination settings: Low, Medium, High(usually 50 watt, 100 watt, 150 watt). A three terminal socket is for a light with more than one bulb i.e. a Gone With the Wind lamp where you turn on the top light, then the bottom light, then both, then off.
the logo for the lamp repair shop in south portland, maine.