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What Size Screws Do You Need for a Light Fixture? (Answered)

Light fixtures are usually called in general the “Lamps”. These can range from table lamps, desk lamps, and even ceiling lamps. In more technical terminology, the lamp can be the source of which can be casually called the light bulb. 

Many people from different walks of life have different designs of different light fixtures.

Some are extra in design, some are minimalistic. Even then the urge to have more of them in the house is not overlooked. Therefore, many people tend to have a few of them on their homestead. 

Sometimes they might need fixing or just changing the bulb will become a necessity down the road of time.

Only then we can understand the need to know what size of screws one must need for light fixtures. We are here to solve that mystery and go into a bit more depth about the topic to help you decide which size of screws you might need for light fixtures.

What size screws do you need for a light fixture?

In most cases, the screws for different electrical instruments or devices can vary a lot. Sometimes the simple change of region can affect the type of screw size as well. On electrical boxes in general, screws are usually 6-32. However, we should also expect 8-32 and even 10-32.

As a general rule for the diminishing of hassle in working electrical devices. There is always a standard and universal size of measurements that are needed to be followed for the ease of access for different people from different regions.

Here are the sizes for two different light switch devices, the plate, and the box both have almost similar size screws, although sometimes they do differ from each other a bit.

Screw for light switch plate: 

The general sizes of screws for the light switch plates are the quarter-inch screws that have a 5/16” length without the screw head. The length as well as the standard slotted oval head is 5/16”. However, the length can sometimes vary between +/- a 1/16”.

Screw for light switch box: 

The standard screws for the light switch boxes are 1/2” long. The box mount is – 3.281” or 3-9/32”, these are the usual spacing for the mounting of standard electrical boxes. 

Moreover, this is also typical for the blank or louvered wall plates, cable covers, and phones. These have a standard size screw of ½” long.

What size screw for ceiling light and pool light?

There are different screw sizes for different aspects of our electronics and outlets. The screw on the garage door equipment and the pool light screw is different due to the circumstances of their environment. 

This is also because of different requirements for the equipment the size of the screw differs.

The standard size for pool light is the 78104800 Brass Pilot screw of the size 1.4 x 1.3 x 0.3 inches. Then we have the other part of the living experience that we take for granted. 

That is the ceiling lights, we need them almost all the time and thus we live with them most of the time too.

Moreover, the light screws for the ceiling lights, the size is 8-32 machine screws. To be honest, this screw size applies to almost every type of ceiling box.

Are light fixtures universal?

Light fixtures most of the time are a hassle that people do not want to get involved with at any cost. There are so many different equipment and locations that require different tools to even start to work.

Thus, people made sure they do not take part in this problem and just make almost all of the light fixtures universal. This eliminated all those hassles and made working with such lights and other electrical switches, it has become much more manageable and less of a hassle.

Furthermore, the ceiling light boxes all have the same size of screws, those boxes almost all the time have three wires that need to be disconnected or connected. The usual screws that are usually used on these lightboxes are always between 6-32, 8-32, and 10-32.

How to know which size screw to use?

There are not many things that can go into finding the right size of screw you have to use in your electrical outlets or devices. That is because most of the screw sizes for those devices are universal and thus it is an ordeal without any hassle. 

The Head: 

Different sizes of screws have heads that are vastly different and some of them serve a different purpose. The design and size of the head also affect the size of the screw. 

Thus, you should make sure what type of head your screws have that way you will be one step closer to the type or size you need.

The Material: 

Depending on the screw material the size of the screw might be varied. 

To make the right size of screws you need, make sure to check on the environment and allow yourself to understand which of the materials will be best for the environment you are currently in. That way you will be able to pick the right size of screws.

The size: 

The usual rule a general electrician uses as a rule of thumb is that the screw should at least enter half of the thickness of the material it is penetrating. For example, a 3/4” screw will go into a 2×4. 

There is also the factor where the screw’s diameter or even the gauge can be taken as a reference.

How to screw in a ceiling light fixture?

Modern ceiling light fixtures are relatively very easy and simple to work with. There are a multitude of steps that you need to follow to change the ceiling light fixture and screw it back in.

Turn off the power: 

We turn off the power in the circuit breaker or the fuse breaker. This is the first step we need to do before doing anything else as this is by far the most important step among them all.

Double-check the switches: 

Double-check the switches in the rooms and turn them on and off to make sure they are turned off. Then we take a pair of rubber gloves and proceed to the next step.

Take off the old shade: 

We carefully take off the old shade of the ceiling light fixture using the rubber gloves. Then remove the light bulbs as they are hazardous because they are made of glasses in most cases.

Carefully use tape: 

Carefully use tape to low hang the light fixture. Then we proceed to wire together all the ground wires.

Attach the wires: 

Make sure the hotwires from the light are wired to the junction’s red wire. We do the same for the white wires from the light and attach them to the white wires from the junction box.

Take off the tapes: 

Take off the tapes and push the light fixture into the junction’s mounting screws that come through the light fixture. Then turn the fixture in such a way that the mounting screws go in the smaller part of the keyhole.

Screw in the light fixture: 

Now we can finally use the screwdriver and screw in the light fixture to the mounting mechanism of the junction box.

Install the light bulbs: 

Carefully install the light bulbs and put on the new shade and light fixture in place.

How to remove a ceiling light fixture with no screws?

There are multiple types of fixtures when it comes to lights on the ceiling that have no screws. Mainly there are four different types of connections or mechanisms that are functional and widely used by other people.

However, the standard process is just to get a pair of rubber gloves to avoid shocking yourself and also to get a better grip. Then proceed to rotate the fixture anti-clockwise to open the device. Moreover, let us look at the different ways we need to do for the other mechanisms below.

Notch or Groove Mechanism:

In this method, we need to twist and pull down the light fixture.

Spring-Loaded Mechanism:

This is a method where we need to pry the ceiling light fixture by pulling as well as nudging.

Slotted Connectors:

This particular type of connection of light fixtures just needs a turn and pull down.


Might be one of the easiest among the bunch is the flush mount type of ceiling light fixtures. This just needs a turn and lowering of the light.

Final thoughts

The electrical boxes on the ceiling can be of certain sizes in different regions but there is still a universal range of sizes that most of these devices and light fixtures use. Those sizes are 6-32, 8-32, and 10-32. Any one-off of these sizes will be the correct one for most light fixtures.