Most houses have walls constructed of drywall. When mounting things to drywall one of the more popular options is to use wall plugs. Wall plugs help prevent screws from pulling free from the drywall material, however knowing the proper size can be challenging.
Below is a chart to guide you for proper drill bit sizing for wall plugs:
|Wall Plug Color||Drill Bit (mm)||Screw Size|
(Source: DIY Doctor)
To use a wall plug, you’ll need to properly drill a hole with the corresponding size drill bit and then install the wall plug. To mount furniture using the plug, you’ll insert a screw of the appropriate size for the plug.
Wall Plug Sizes
Wall plugs come in a variety of different shapes and sizes, and you’ll want to pick the right size for your piece of furniture. Once you’ve selected a wall plug, you’ll drill a hole of the corresponding size.
Selecting The Right Size Wall Plug
Selecting the right wall plug to use is determined by the screw for your mount. If your screw and your wall plug are not compatible sizes, then the plug will not be able to support the screw, and you won’t be able to mount anything.
You should use a yellow plug for 4-8 gauge screws, a red plug for 6-10 gauge screws, a brown plug for 10-14 gauge screws, and a blue plug for 14-18 gauge screws.
You also need to use a plug long enough for the screw to fit in. The wall plug should be around the same length as, or longer than, the screw that you want to insert.
Once the plug is secured in the wall, you can mount your furniture using a screw. The screw doesn’t need to go all the way into the wall plug, but it should almost fully go into the wall for your item to be secured.
How Much Weight Your Wall Plug Can Hold
You don’t want to overload your wall plug by putting too much weight on it. A standard plastic wall plug can hold between five and twenty-five pounds, with larger plugs able to hold more weight.
Wall plugs also come in other materials, such as nylon or zinc-coated metal. These will also hold more weight than plastic wall plugs.
Even with a strong wall plug, your plug can only hold as much weight as the wall. If you’ve installed your wall plug into drywall or plaster, be careful not to put too much weight on it because the wall itself can break, even if the plug does not.
Do not use a standard wall plug to mount vertically in a ceiling, as the plug will loosen and fall out. For that, you’ll need another kind of fastener.
How to Drill A Hole For Your Wall Plug
To mount cabinets, TVs, and other furniture on a wall plug, you’ll first need to drill a hole for the plug to fit in.
Before you drill the hole for the plug, you’ll want to begin with a smaller hole to guide your drill, called a pilot hole. Using the table above, find the appropriate drill bit for the wall plug that you would like to install, and then, for the first hole, use a drill bit a few sizes smaller. Make sure to use a masonry drill bit on stone or brick walls.
Holding the drill at a 90° angle from the wall, drill a pilot hole into the wall. If you are drilling into drywall or plaster, I’d suggest holding a hoover below the hole as you drill since dust will come out. After you’ve drilled the hole, go over it with a hoover to remove any dust inside.
Now use the drill bit size designated for your wall plug. Drill into the pilot hole that you just created. The drill should enter easily, without much resistance, and widen the hole. After you’ve widened the hole, go over it once more with a hoover to make sure that all the dust is removed.
Inserting Your Wall Plug
Now that you’ve drilled a hole for your wall plug, you’ll insert the plug into the hole to install it. Insert the wall plug with the closed-end first.
If you’ve used the right size drill bit, then you will have a little bit of resistance as you put the plug into the wall. The teeth of the plug should be around the same size as the hole, and they will catch on the hole as you insert the plug.
Insert the wall plug as deeply as you can with just your hands. If the plug does not go in all the way, gently tap it with a hammer. If it still does not go in, widen the hole using a drill bit one size larger.
When finished, the wall plug should be fully inserted into the wall. The open end of the plug will be right at the opening of the hole you drilled.
Unknown Wall Plug Sizes
Occasionally, you may come across a wall plug that is not one of the colours listed in the table above. A simple test can help you determine the drill bit size needed for wall plugs of unknown sizes.
Get a piece of cardboard. Select a drill bit that you think is approximately the size of the wall plug. Drill a hole into the cardboard, being careful not to move the drill sideways and widen the hole larger than the bit. See how well your plug fits in the hole.
If the hole is not big enough for the plug to fit in, then try drilling a new hole with a larger drill bit. If the hole is too large, the wall plug will fit in easily, but the teeth won’t catch on the hole as you insert it. Try drilling a new hole with a smaller drill bit.
When the wall plug fits in the hole, with the plug’s teeth catching on the hole as you insert it, then you’ve selected the right size drill bit. Use this drill bit in the wall when you widen the pilot hole, as above, to drill a hole of the appropriate size for the plug.
Other Wall Fasteners
If you’re looking for a mount that will hold more weight than plastic wall plugs, you have a few options.
Threaded drywall anchors are made of nylon or zinc-coated metal, and to use them; you don’t have to drill a pilot hole. You can insert the anchor using a screwdriver or drill, and it can hold between 25-75 pounds, depending on its size.
Molly bolts are useful because they allow screws to be removed and reinserted into the wall. Installing molly bolts requires a pilot hole. They can hold between 25-55 pounds, depending on their size. Molly bolts can be used to hang light items from the ceiling, such as smoke detectors.
Toggle bolts can hold the most weight. Metal toggle bolts can hold up to 100 pounds, and plastic ones can hold up to 20 pounds. Toggle bolts are the hardest to install, requiring a hole 3x the diameter of the bolt. They can be used to hang heavier items from the ceiling, but this is not recommended as the ceiling drywall can break.
To mount your new cabinet, TV, or another piece of furniture onto your wall, you’ll want to select the right wall plug or fastener for its weight. Then, you’ll drill a hole into the wall using the appropriate size drill bit, insert the wall plug, and use a screw to mount your new furniture.