I moved into an apartment maybe a year ago, and noticed many lightbulbs were out. When I went to unscrew them, they simply broke off (not shattered) in my hand. It was like someone had scored the glass right where it connects to the metal. In addition, there was a significant buildup of corrosion along the inside of the metal part (I don't have any pictures of how they look, but I'll try to add one the next time this happens).

I thought that was pretty weird, but I finished replacing them anyway (the metal parts remained stuck in the fixture so I had to use a pair of pliers to unscrew them). Ever since, another bulb breaks in the same way every month or so. This happens in multiple rooms, so I don't think it's one incorrectly wired fixture. I've also tried 60W and 75W lightbulbs (just your everyday incandescent bulbs), but that doesn't seem to matter.

Why might my lightbulbs be breaking in this way? Is there anything I can to stop it?

I have a theory that my lightbulbs aren't the proper wattage for my fixtures, and the excess current is causing the corrosion, which in turn destroys the connection between the metal and the glass, but I don't know much about lightbulbs. If my theory is right, is there a way to determine which watt bulb to use?

  • 3
    It's fate telling you to move on from conventional bulbs to something less energy-gluttonous. Why not switch to LEDs? Regarding your theory (hypothesis), no. Fixtures can take any wattage up to a point at which they become a fire risk due to heat buildup in surrounding materials. It shouldn't affect the glass at all, though. They're always screaming hot.
    – isherwood
    Nov 10, 2017 at 20:00
  • You say you've also tried 60 and 75w bulbs. What was in there before? What's the fixture rated for?
    – isherwood
    Nov 10, 2017 at 20:25
  • I'd also check the voltage coming to the apartment at the light fixture or any outlet. Higher than normal voltage will make bulbs burn hotter and fail prematurely. It's not common, but it does happen and could be silently damaging other electronics as well.
    – JPhi1618
    Nov 10, 2017 at 20:32
  • I have sometimes seen in the past this happening with non GE brand bulbs, but it has been over a decade since I used incandescent in primary fixtures Nov 11, 2017 at 0:22
  • Not an answer to the main problem, but I've read that a potato pushed into the remains of a broken bulb is a good way to remove the base of a broken bulb. I think the idea is that the potato is more likely to immobilize bits of broken glass than pliers, particularly beneficial with overhead fixtures.
    – Steve
    Nov 11, 2017 at 0:25

4 Answers 4


Depending on the fixture you may have a lamp with too much wattage. Most fixtures can handle 60 w lamps but recently I have run across some 40 w fixtures. There should be a stamp inside the fixture listing the max wattage. Too much heat will cause the problem you describe. Added I normally do not use lube below 400w lamps but do use dielectric grease on 400 & 1000 w lamps if having problems removing lamps an electrical grade of grease used sparingly cannot hurt.


There are certain designer bulbs I have used that do that. Sylvania 40-Wt. "flame-shaped" bulbs are bad about it. What I believe is they are best suited for up-mount rather then down-mount. The heat concentrates at the base when used in a down-pointing fixture.


Aluminum against aluminum is very prone to galling ; inexpensive fixtures and bulbs often use aluminum for the socket/ thread so they "stick ". It is actually welding on a microscopic level. Look for bulbs with brass threads. And put graphite on the threads ( not grease or oil because they are poor conductors ) . Graphite with a little oil as a carrier is OK. MoS ( molybdenum sulfide) will also work . I happen to have MoS power which I have used for years , but it is not readily available. Nothing to do with wattage.

  • In an apartment, I would expect inexpensive fixtures. Actually, I'd expect them pretty much everywhere except products from fancy lighting stores, in fixtures that have been replaced by people who are aware of this issue, and fixtures old enough that manufacturers hadn't thought of cutting costs this way.
    – Steve
    Nov 11, 2017 at 0:31

Before insertion of each bulb lube the threads with a small amount of silicone grease. You can get this in a small foil packet at the auto parts stores. They are used to lube auto bulbs to prevent corrosion. The grease is non-conducting but the threads bite through and make electrical contact. Screw them in firmly but not "hard".

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