All of my ceiling fixtures have porclean sockets which are deep and incandescent bulbs have a longer thread base to make contact at the bottom of the deep socket. More than half the ceiling fixtures (with 2 to 6 sockets each) in my home will not work with led bulbs because the base threads are shorter in length and can not screw deeply enough into the socket to make the bottom connection.

Is there anything I can add to extend the led bulb thread base by approximately 1/16th or 1/8th of an inch; or screw something into the bottom of the porclean socket to raise the height of the connection point on the bottom to make contact with the led bulb?

  • 6
    Please edit to make this mixed case. All-caps is hard to read, and on the Internet is usually reserved for "shouting".
    – keshlam
    May 27, 2023 at 4:11
  • Are these all the same brand of bulb? They have slightly different base designs.
    – KMJ
    May 27, 2023 at 5:22
  • 1
    Try a different brand of LED with a slightly different shape?
    – Huesmann
    May 27, 2023 at 12:11

3 Answers 3


You can't generally extend either end. But what has worked for me, is to

  1. Flip the circuit breaker off
  2. Ensure the socket is dead, with a voltmeter or old light bulb
  3. There is a piece of angled metal bracket at the bottom of the socket, use pliers to bend up the free end, gently. It doesn't matter if you bend up by more than 1/8 inch. It will push back when the bulb goes in.
  • I encountered this when I changed the bulb in my garage door opener to LED, and bending that little metal tab at the bottom outward a little bit fixed it for me.
    – Gaston
    May 28, 2023 at 17:35
  • #1 and #2 are the most important. You're literally sticking a fork in a socket at this point, so you better test and re-test that it is definitely off. I would just test it every time you touch the socket out of habit. It'll save your life. Happened once when working at a junction box I thought was off, and I'm so glad I developed the habit.
    – Nelson
    May 29, 2023 at 3:17

Incandescents generally have a long thin neck. LEDs generally have a squat little compartment at the bottom for the driver.

Often it is not the thread that is too short, but rather, something in the fixture is colliding with that fat little driver compartment.

They do make LEDs that have the longneck base style. They are typically the "filament style" LEDs that look old-fashioned. These aren't necessarily found on the bottom shelf of the dollar store, though.

  • The filament style LEDs are (usually) also more energy efficient and likely to last longer than the older COB-style bulbs, and they'll provide (nearly) omnidirectional lighting without a diffuser. Unless you specifically need the compactness and directionality of a COB LED for something like a spotlight, I'd advise getting a filament bulb anyway. May 29, 2023 at 8:26
  • (Caveat: Like anything else, some filament LED bulbs can be cheap crap, too, and for LED bulbs "cheap crap" typically means "wastes energy, overheats and dies quickly". Get one from a reputable manufacturer and check the EU energy label or local equivalent, if there's one where you live, or just calculate the lumens / watt rating yourself.) May 29, 2023 at 8:30

You might be tempted to use a washer or a coin or some other conductive material as a spacer.


You're risking shorts if the spacer moves during lamp-threading or later, and arcing due to imperfect connections.

Your real fix is to update the old deep ceiling fixtures with something thinner, allowing a larger range of lamps in the future.

  • 1
    I've done this, however I soldered it onto the end of the bulb so it couldn't go anywhere. colored Christmas flood lights that wouldn't go all the way into the sockets. May 29, 2023 at 3:28
  • 1
    @SpehroPefhany With respect, extremely unwise. A washer, coin or whathaveyou is unlikely to be compatible with low-temperature soldering in the medium term, and any joining process effective on a washer or coin (brazing, welding) will damage or destroy the relatively fragile wires etc. inside the bulb. The ONLY correct answer is to make sure that the outline of the bulb and recess are compatible. May 29, 2023 at 8:18

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