What is an E27 socket?

E27 is the classic screw socket: the bulb you turn into the holder with a twisting motion. The E stands for Edison, the 27 for the diameter of the thread in millimeters. It is still the most widely used socket for loose lamps around the house.

How to recognize it

An E27 lamp has a metal screw base with a spiral thread around it. You turn it clockwise to tighten. That sets it apart immediately from the two other sockets you meet in a home:

• E14 — the same thread, but 14 mm instead of 27. The small socket, often in chandeliers and table lamps.
• GU10 — no thread but two pins with a thickened end. You push it in and turn a quarter turn. This is the standard for spots.
• G9 — two thin loops you push straight into the holder, without turning. Small and widely used in wall lights.

Where we use E27

In our range you mainly meet E27 on pendant lights and the occasional wall light:

• Fumo pendant light — three E27 sockets under smoky glass, €82.95
• Trivo pendant light — three-light, 12 watts, €44.95
• Filo pendant light — adjustable up to 160 cm, €21.95
• Scallop wall light — single-light in beige, €31.95

None of these fixtures come with a light source. That is stated for a reason: you choose the bulb yourself, and with it the light color, the number of lumens and whether it dims. We do stock one in our accessories: the LED Filament E27 bulb of 4 watts in amber at 2200K, dimmable, €8.95. If you want something brighter or whiter, you buy that elsewhere.

That also makes E27 the socket with the longest life in your interior. If you do not like the light, you screw in a different bulb instead of buying a new lamp. Above a dining table that is exactly what you want: the fixture hangs there for ten years, your taste in light changes sooner.

What E27 does and does not tell you about the light

The socket only says something about how the lamp is held in place. Nothing about how bright it is, what color light it gives, or how long it lasts. Two E27 lamps can put out 400 and 1,500 lumens and look identical from the outside.

So when buying an E27 lamp, watch three things: the number of lumens, the color temperature in Kelvin, and whether the packaging says dimmable. Screw a non-dimmable lamp into a fixture on a dimmer and it will flicker or not come on at all.

Also check the maximum wattage the fixture can take; that is on a sticker inside the shade or in the manual. With LED you rarely run into it in practice, because an LED lamp needs about a tenth of the power of an incandescent bulb for the same light. With a fixture holding three sockets, such as the Fumo, the consumption of all three lamps does add up.

E27 or integrated LED

The alternative to a socket is the integrated LED: a fixture with the light source built in and not replaceable. That saves the bother of buying lamps, but when the LED gives out you throw away the whole fixture. Our catalog holds seven with integrated LED and one that is explicitly not replaceable.

The Baro pendant light is an example: a 120 cm bar putting out 3,000 lumens at 30 watts. You never have to screw a bulb into it, but you cannot change the light color later either.

Can an E27 lamp go in a spot?

No. A recessed spotlight is too shallow for an E27 bulb and the holder is different. Spots work with GU10, MR16 or an integrated LED. To find out which of those suits your ceiling, see the recessed spotlights collection or read GU10 or integrated LED: what should you choose?

For pendant and wall lights it is the other way round: there, E27 is the socket that gives you the most freedom. Have a look at the pendant lights and the wall lights for the options.