A few hundred years ago, when people built their homes and buildings, they had a screw to choose from. There are dozens of different types of screws used in the construction industry today and using the wrong one can mean the difference between a job well done and a job that doesn't meet current standards.
Almost all screws are made from steel and most are coated to make them more durable. Stainless steel and solid brass screws are two screws that naturally resist corrosion and are better than other types of screws because they do not have a protective layer that can wear out over time.
The size of the screws depends on the type you are using, but many of them are available in multiple sizes. Screws are measured in length and gauge, which is their diameter. When measuring the length of a screw, the type of screw will determine how the length is measured. Wood screws, drywall screws, deck screws, and any other screw that sits flush with or slightly below the material when screwed in has a length that includes the measurement of the entire screw.
Sheet metal screws and set screws, the two most common screws that leave the head on the surface of the material, determine length by measuring from the tip of the screw to the bottom of the screw head.
When it comes to the types of threads that many screws have, they are categorized in a few different ways. Sometimes you'll see screws labeled by the number of threads per inch or the distance between each thread. However, you will mostly see them labeled as thick, which is deeper strands, and thin, which is closer strands and not as deep.
5 main types of screws used in construction
A wood screw is a type of screw that has coarse threads, which hold the wood securely. This screw creates a tight connection when you attach wood to wood. As you drive the screw into place, the threaded end bites into the underside of the wood and continues to do so until the two pieces of wood are firmly joined.
The top part of the screw, or smooth part, will not grip the wood and will instead rotate until the screw is flush with, or sometimes just below, the surface of the wood.
There are many different sizes of wood screws, so you should choose the one for the job you are currently doing. The most common wood screw size is #8, which has a diameter of approximately 5/32 of an inch.
The best thing about these types of screws is that they are available for both indoor and outdoor projects. Exterior wood screws are treated with zinc or galvanized, so they won't rust in the elements.
2. Drywall Screws
Drywall screws do exactly what they sound like they do: attach drywall to wood studs or beams. These types of screws are available anywhere from one inch to three inches and a special drywall drill bit is required to install them. You won't need to pre-drill holes to insert these screws, as drywall screws fit as soon as they reach the studs or studs.
It's important to know that if you are using these types of screws to attach drywall to metal studs, you should purchase drywall screws that state they can be used for this method.
3. Masonry Screws
Masonry screws are also called anchors and you will immediately notice that they look quite different from other types of screws. They do not have a tip on the bottom and some will require the use of a hex bit instead of a Philips head. These screws are used to attach metal or wood to concrete and holes must be pre-drilled before inserting these screws and securing them.
4. Deck Screws
Deck screws are primarily used to secure the floor of a deck to the deck joists. These types of screws are similar to wood screws but are self-tapping and available with star and Philips heads. The type of decking material you use will determine which decking screws you need to purchase.
Pressure-treated wood requires an ACQ-compliant deck screw, while composite decking materials generally require stainless steel deck screws.
5. MDF Screws
MDF screws are often used in medium-density fiberboard materials, which make up much of the interior trim of homes and buildings. Medium-density fiberboard materials are harder than solid wood, which means regular screws will split the material.
Although you can use regular wood screws by simply pre-drilling all the holes, you can save a lot of time by purchasing and using MDF screws.
Other types of screws used in construction
- Fixing screws
Set screws are heavier screws used for wood and are primarily used for outdoor projects that include playgrounds, fences, and garden structures. Most of the time, you'll want to add a washer under the head to increase strength and make the final assembly look nicer.
- Wood Screws
Currently, wood screws are commonly used instead of lag screws since they have coarse threads and are long. These types of screws are stronger than many other screws available, making them perfect for structural construction.
- Sheet Metal Screws
Sheet metal screws can be used for all types of thin metals and are available with many different thread types and head shapes. Shorter sheet metal screws are perfect for gutters, while those with oval heads offer a finished look.
- Machine Screws
Machine screws look like a screw in that they have a blunt tip and are often used to join plastic or metal together. These types of screws are not made for wood, so don't try to take the easy way out when these are the only screws you have on hand.
- Concrete Screws
Concrete screws have a high-resistance coating, in addition to an exclusive thread that allows them to adhere to concrete and many other materials used in masonry. These types of screws are available with two different heads.
The hex head is best for surface installation, while the flat head is perfect for those times when you need the screw to sit flush once installed.
Now that you know the different types of screws used in construction, you can easily carry out the work you are doing with the right ones. You'll also no longer have an excuse for using the wrong screws, as you now know why each one is better for certain jobs than others.
