Screw Buying Guide
Screws are extremely useful in construction and other industries — they provide secure, tight fastening and are easy to adjust and remove, making them a suitable choice for many jobs. These fasteners come in so many types, materials and sizes that choosing the right screw for your project involves a few considerations.
Below, we’ll walk you through all the different types of screws and provide tips on how to choose the right screw size and length.
Types of Screws
To handle a construction job efficiently and safely, you need more than the proper tools — you also need the right fastener. Screws are excellent for bringing materials together, but there are many types available, each of which is best suited for a specific job. You can consider screws in two categories — general and specialized.
General Screw Types
When choosing screws, you might start with the general fastener category. These screw types suit various projects and include:
- Wood screws: Wood screws have sharp points and are used to fasten two pieces of non-structural wood together. The threads on these screws are coarse and feature an unthreaded shank next to the head. This unthreaded portion allows the wood screw to bring the two pieces of wood tightly together.
- Drywall screws: These screws are threaded fully and designed for interior jobs like fastening drywall to studs. Drywall screws with coarse threads are meant to attach drywall to wood studs, while ones with fine threads are for securing drywall to metal studs.
- Cement board screws: This fully threaded screw type is designed to fasten a subfloor for tiling jobs or backboard to studs on a wall. They feature a coating that provides resistance to corrosion, which can be caused by moisture or mortar. Cement board screws can work with metal, wood or both.
- Deck screws: These screws are used for fencing, decks and other jobs outside. When choosing deck screws, keep in mind there are two common types. Wood deck screws have a coarse-threaded portion and unthreaded shank, and composite deck screws feature a smaller head and finer threads. Some composite deck screws feature an additional thread set to prevent the composite materials from mounding at the screw’s head.
- Structural wood screws: A structural wood screw shares the same basic design as a normal wood screw with an unthreaded shaft and coarse threads. But these screws are considerably stronger. You can also use them like lag bolts or screws if the local building codes allow it.
- Lag bolts or lag screws: A lag screw or bolt fastens heavy components or materials that handle heavy loads. They feature hex heads, meaning you need a socket and ratchet or wrench to install them. Eye lag screws are also common, which are wood screws that have rings on their head to secure a chain or rope.
- Machine screws: These completely threaded screws are designed to fasten together metal components. There are several kinds of machine screws, including socket cap screws, which feature cylindrical, raised, hex-socket heads, and socket set screws with no heads but rather internal hex sockets.
- Concrete screws: A concrete screw is made to fasten in masonry, such as concrete. Self-tapping concrete screws are available, which you can drive into a material directly without the need for pre-drilling. There are also types available that work with masonry anchors.
- Sheet metal screw: These completely threaded screws are used to secure two pieces of sheet metal or sheet metal with softer materials. This screw type is often available to use with a pre-drilled hole. There are also sheet metal screws that come with self-drilling points.
- Multi-material screws: A multi-material screw includes features for use in sheet metal, wood, masonry, drywall, plastic and various other materials.
Other than the common screw types above, there are several different kinds of screws available, most of which have specific applications. These include:
- Ceiling fan screws: This screw type fastens the light globes or blades of ceiling fans.
- Cabinet mounting screws: These screws are specifically designed for fastening cabinets to wall studs.
- Gutter screws: This screw type fastens the components of a gutter together and also fastens the gutters to the sides of a house.
- Dowel screws: This headless screw has threads and points on both of its ends. It is designed to attach wood pieces together with no visible fasteners.
- Landscape screws: These long screws are used to connect landscape timbers.
- Wall plate screws: This machine screw fastens the covers for outlets, light switches and other similar components over an electrical box.
- Trim screws: A trim screw features a tiny countersinking head, allowing it to be easily concealed.
- Security screws: Security screws are designed to be difficult to remove. Doing so requires a specialty bit or driver.
Screw Finish and Material
Material and finishes are two important characteristics of a screw and often determine what jobs the fastener is suitable for. While some materials allow a screw to handle demanding jobs, others help prevent corroding or rusting. If the screw’s material is prone to rust, certain finishes can protect it from corrosion.
The most popular screw material is steel, but steel experiences corrosion when exposed to moisture. For this reason, a steel screw requires a plating or coating that’s resistant to corrosion. Popular finishes and coatings include black phosphate and zinc-plating.
A variety of other finishes are available, including polymer, electro-coated paint, powder-coated paint and ceramic that help prevent a steel screw from corroding. Decorative finishes like chrome, nickel plating and brass feature some protection against corrosion, but they are not recommended for outdoor applications. Bright steel screws do not have any corrosion resistance and are designed solely for interior applications, where moisture isn’t an issue.
Other common screw materials include:
- Stainless steel
Note that some finishes and materials aren’t compatible with certain tasks and needs. Fasteners are often made for very specific applications and don’t work with other ones. Remember to read the manufacturer’s instructions and abide by code specifications.
Types of Screw Drives
Screws feature a number of drive types, with the most common being:
- Phillips and slotted drives: Phillips and slotted drives are two of the most common, although screw heads with these drives tend to easily cam out. There are also combination drives, which work with both types of drivers.
- Allen drives: Screws with Allen drives feature sockets with six sides but also are susceptible to camming out.
- Square and star drives: Square and star drives, alternatively known as Robertson drives and Torx, respectively, reduce the risk of camming out. These drives are excellent at gripping the driver and, in many applications, allow one-handed driving.
- Hex head: Screws with hex heads are driven in using a socket and ratchet or wrench.
Types of Screw Threads
If a screw has coarse threads, there is more space between the threads. These fasteners tend to work with softer materials, such as drywall or wood, although sheet metal screws feature coarse threads, as well. You can install and remove screws with coarse threads rather quickly.
If a screw has fine threads, it’s most likely meant to be used with nuts or for pre-tapped holes. The smaller gaps between each thread provide the screws with a tighter hold, although installing and removing them takes more time.
Types of Screw Heads
The heads of screws also come in various types and serve different purposes. Some heads fit shallow depressions known as countersunk holes. Other heads, such as those of bugle-head and flat-head screws, are designed to rest flush with the workpiece’s surface. There are also self-countersinking screws, which cut the countersunk hole while you’re driving them.
Other than countersunk screw varieties, there are non-countersunk screws with pan or round heads to sit on the workpiece’s surface. There are also trim-head screws with tiny heads, which means you can conceal them more easily than other fasteners. Screws featuring washer heads, wafer heads and truss heads provide a larger area of contact underneath the head of the screw than other types of fasteners.
How to Choose the Right Screw for Your Project
With the most common types of fasteners in mind, it’s time to decide how to choose a screw for your project. To make the right selection, follow these tips:
- Pick a drive style: As you learned above, there are many different drive styles of screws, including Phillips, flat head, torque and square. Torque and square heads, for example, will make it easier for your drill bits to stay in place and help prevent stripping and slipping.
- Pick a size: Pick a screw thickness suitable for both the weight the screw must support as well as the width of the material you’re inserting the screw into.
- Figure out the right length: When choosing screw length, pick a length based on how deep the material is you’re inserting the screw into. When measuring the screw, measure from underneath the head of the screw to the point. Once again, you should consider how much weight the screw will have to support.
With the right fastener choice, you can have better success with your project. You’ll be able to work efficiently and avoid having to start your project over.
What Is the Nature of Your Project?
Each screw type is designed to serve a specific purpose. When choosing screws, you’ll need to know what type of project or projects you’ll be taking on and what materials you’ll be using. Screws are first categorized based on the materials on which you can use them. The most commonly used screw types include:
- Wood screws: These fairly coarse screws feature relatively large spaces between threads. Large versions of wood screws also have an unthreaded shank next to the head. Some wood screws also feature a subtle taper from head to tip. Woodworking and other wood-based projects could benefit from these fasteners. Wood screws are not case hardened so they are softer than case hardened screws.
- Drywall screws: Drywall screws are characterized by the easily noticeable curve on the junction that connects the shaft to the head called a bugle head. This curve keeps the drywall from tearing when the screw is inserted. Both fine- and coarse-threaded drywall screws are available. The coarse-threaded versions are meant for securing drywall to wood shafts, and the fine-threaded ones are used to connect drywall with metal shafts. Consider the nature of your building project to choose the right drywall screws.
- Sheet metal screws: Sheet metal screws tend to feature threads all the way from the head to the tip, meaning the threading is not interrupted. Some feature self-drilling or self-tapping tips, which is particularly helpful if you haven’t made any drill holes. Construction, roofing and HVAC industries may use these fastener types. Sheet metal screws are case hardened for additional strength.
Remember, a variety of screw types exist in general and specialized categories. Your job site may require a few different styles to complete your tasks.
How to Choose the Right Screw Size
Once you’ve narrowed down the right screw type for your project, you’ll need to determine the appropriate size. Screw size includes both the fastener’s length and width.
When looking at screw sizes, you may see the word “gauge,” which refers to the width or diameter of a screw. Screw gauges commonly range between 2 and 16, with 8-gauges being a good general-purpose size. If you’re working with particularly heavy materials, you’ll want to use a 12-gauge or 14-gauge screw, and for finer applications like woodworking, you may not need anything more than a 6-gauge.
To understand how to choose a screw size, have the drive style you want in mind and follow these steps:
- Pick the screw gauge: The gauge you choose will partly depend on how wide the material you’re screwing into is as well as the weight the screw must support. Thicker screws will support more weight, but they also must be anchored in more material.
- Pick the screw length: Ideally, you should choose a fastener that’s about half as long as the material it’s going into. If the screw is less than half the length of the receiving material, it won’t anchor properly. If you pick a screw that’s much longer than half, you may damage the other side of the material.
Shop Our Screw Options
At All Points Fasteners, we offer top-quality screws for every application. Whether you’re hanging drywall, installing gutters or building a deck, we have the fasteners to make your project a success.
Wood Screws vs. Metal Screws
When you have a job to do, knowing the right tools and supplies to use will help you complete your tasks as efficiently as possible. Even the screws you use play a crucial role in securing your build, and there are hundreds of varieties to choose from.
Nearly all types of fasteners boil down to two essential types — wood and metal screws — each with unique properties that are beneficial in certain situations. Understanding the differences between wood and metal screws will allow you to make the most of your time on the job.
Commonalities Between Metal and Wood Screws
Before we compare wood screws vs. metal sheet screws, it’s worth acknowledging what these two varieties have in common. Both wood and metal screws serve similar purposes — fastening objects together. They often have similar or identical metallic compositions and are available in standard lengths between 0.25 and 3 inches. Both types of screws are drivable using the same tools, like screwdrivers or power tools, and come with flat, round, oval, Phillips and other head shapes.
While they are alike in function and utility, wood and metal screws feature different properties that distinguish them for their specific roles.
Wood Screw Features
Wood screws are similar to metal screws in some ways, but their differences allow them to serve a specific purpose. As the name would suggest, wood screws are best for fastening materials like plywood, lumber or other types of wood. A few key design features make wood screws ideal when working with these softer materials.
For one, wood fasteners feature coarse threading (fewer threads per inch), usually only up to an inch in length. Additionally, wood screws feature smooth shanks or threadless sections underneath the screw’s head. Wood screws’ partially threaded design allows for a strong hold, and it also stops the screw from turning when the thread runs out. A screw can split or crack wooden material if it drives too far, so partially threaded shanks protect your materials while providing a firm hold that lasts.
Metal Screw Features
Metal screws differ from wood screws in their design and specific function, featuring design elements geared toward fastening metal-based materials and hard plastics.
Metal screws feature longer threads than wood screws, usually at least two inches in length. These longer threads also have a higher pitch — or threads per square inch — and they cover the entire body below the head.
Since they frequently serve to fasten materials like sheet metal, metal screws are often self-tapping. Few metal materials are pre-drilled with holes, so it’s sometimes necessary to use screws that can create their own pilot holes for maximum efficiency. Self-tapping metal fasteners can pierce thin metals with ease to cut their own threads and provide a firm hold.
Wood To Metal Screws
A relatively new design, wood to metal screws feature wings directly above the drill bit tip of the screw with a machine screw thread of 24 threads per inch. The purpose of these wings is that they will ream out the wood, while the drill bit is drilling through, so that the wood doesn’t bind up in the threads before the drill bit starts drilling into the metal. Once the wings hit the metal, the wings will break off. The reaming process is why we call these reamers.
Find Premium Wood and Metal Screws at All Points Fasteners
In summary, metal and wood screws have a lot in common regarding their size options and general function, but they feature design elements for unique situations. Wood screws have coarser threads with smooth shanks below the head, while metal screws consist of finer threads that cover the entire body. While you can use either screw for any job in a pinch, these fasteners deliver their best performance when used for their intended purposes.
Are Stainless Steel Screws Rust Proof?
When you have a job to do, it’s a great feeling to know that your work will last. Fastening outdoor fixtures with durable, rust-resistant screws will keep your projects in better shape for a longer period without the need to swap screws every season. While many manufacturers attempt to design rust proof screws using different materials or techniques, only certain fasteners can offer optimal rust resistance. So, what screws are rust proof?
When it comes to rust-resistant fasteners, stainless steel screws are the absolute best option. Stainless steel screws contain certain properties that allow them to withstand harsh outdoor elements to greater effect. As a result of their rust-resistant design, stainless steel fasteners see use in many outdoor projects.
Continue reading to learn more about the qualities that give stainless steel screws rust proof supremacy and the jobs they easily accommodate.
What Makes Stainless Steel Screws Rust Proof?
Stainless steel fasteners feature unique qualities that result in greater rust resistance than nearly any other variety. The major difference between stainless steel screws and other rust-resistant options is that these fasteners are solid stainless, where others feature a stainless coating on top of a different material. A simple answer is that there are basically two different types of stainless when dealing with screws. 410 stainless (includes some carbon steel to make it stronger and magnetic) and 18-8 (includes all the 300 series of stainless and are non-magnetic).
Stainless steel screws originate from the steel industry’s peak in the early 1900s and have grown to include a few different formulas over time, the most common being ferritic, austenitic and martensitic. These varieties are characterized by their content of minerals like chromium, nickel, titanium and copper. The strongest stainless steel screws have high levels of chromium.
Stainless steel screws achieve elevated rust resistance thanks to their chromium-oxide composition. Fasteners with a chromium oxide coating provide extra resistance to rust and corrosion by using the added oxygen as a protective layer. The chromium oxide coating can deteriorate as contaminants settle on the screw’s surface, but rainwater washes these contaminants away and preserves the fastener’s protective layer. As a result, stainless steel screws are the perfect outdoor fastening solution.
Uses for Stainless Steel Screws
Manufacturers use stainless steel to develop multiple types of fasteners that serve different purposes. Because they comprise such strong, durable material, stainless steel screws find use in numerous applications and are especially useful for outdoor projects. If you’re building something that will face prolonged exposure to rain and other weather conditions, stainless steel fasteners are an excellent option. From building decks to outdoor furniture, sheds, lawn decorations and more, stainless steel screws boast weather-resistant qualities that make them a popular choice outdoors.
Are There Other Rust-Resistant Screws?
Stainless steel screws are the best choice for rust resistance, but there are a few other options that will work in a pinch. The most notable substitute for stainless steel screws are screws that are ceramic coated. Ceramic coated screws offer decent rust resistance thanks to a strong exterior coating, but they lack the fully stainless steel composition that produces the best results. While ceramic coated zinc screws are less rust resistant, they come at a lower price than stainless steel.
Learn More With All Points Fasteners
Stainless steel screws are an excellent rustproof choice for outdoor jobs. At All Points Fasteners, we sell high-quality products that help contractors provide the best services. For more information that will help you chose the right screws and tools for your project, keep up with our blog or contact All Points Fasteners today!
What Is a Self-Piercing Screw?
Self-piercing screws, also known as “zip” screws, are a type of self-tapping screw that cuts its own threads. These screws come to a very sharp point, allowing them to work through materials like metal and wood.
A self-piercing screw can penetrate materials and create its threads simultaneously. They will ‘pierce’ through light gauge metal and do not require pre drilling.
There are two different types of self-tapping screws:
- Thread-forming: The threads push the material aside as they create the path for the screw’s body. They can resist loosening without washers or other devices.
- Thread-cutting: These cut and remove material to create threading. They require less force when drilling since they remove a portion of the substance they’re driven into.
If you need piercing power and want to improve your project time, self-piercing screws might be right for you.
Are Self-Piercing and Self-Drilling Screws Interchangeable?
Self-piercing screws and self-drilling screws should not be used interchangeably. Though they’re often compared to each other or mistakenly considered the same, these two types of screws are quite different, and using one in place of the other can create potential issues. When you are gathering materials for projects, getting the right kind of screw makes a significant difference.
- Have a drill-shaped point at the tip.
- Do not require a pilot hole.
- Work well with metals up to 1/2″ thick, depending on the drill bit tip size. The reduced tip roofing screw is good for use in metal to wood.
- Have a twinfast threaded body leading to a very sharp tip.
- Self pierces up to 26 gauge metal.
- Work well with metals like light gauge steel, aluminum and copper.
The critical difference between the two is the thickness of metal they are designed to be used with, as self-drilling screws can be installed quickly given their lack of need for a pilot hole in thicker metals. Overall, the two should not be used interchangeably, as they have different uses.
What Are Self-Piercing Screws Used For?
Self-piercing screws are preferred in situations where you are using light gauge metal – 30 to 26 gauge. You can use self-piercing screws for sheet metal like steel, aluminum and metal alloys. Self-piercing screws create a tight connection since they make their own path and have a fine, twinfast thread.
There are some self-piercing screws created explicitly for wood that minimize the chance of breakage. These have what’s called a Type 17 or auger point. There is a cut in the tip of the screw that allows displaced material to escape which prevents splitting the grain and damaging the surrounding material.
Self-piercing screws are also ideal for projects that require regular maintenance or when you are fastening two types of material together.
Shop for Self-Piercing Screws With All Points
Depending on your project, you want to find the screw that will give you the best results. Save yourself the effort and contact us for a free quote or to find out more about our complete inventory. We can help you find the perfect fasteners for any project.
The Strongest Screws for Any Project
The strongest screw for a given project will vary based on whether you’re working with metal, wood or other materials. Each type of screw has different strengths that make it a capable fastener. Learn more about the different styles below.
These screws create their own hole as they turn. Self-tapping screws are most often used when attaching multiple layers or sheets, as they usually require no pilot hole and are compatible with many materials, including wood, metal and brick.
Self-tapping screws come in various sizes, materials and styles. Thread-cutting screws do not displace any material, while thread-forming screws will. Generally speaking, the thicker the screw, the more weight it will hold.
Self-tapping screws can be made from carbon steel or stainless steel. Carbon steel can be plated with zinc to improve their resistance to corrosion. You can also find self-tapping fasteners made from aluminum usually used with aluminum siding.
Wood screws comprise a head, shank and threaded body, and they’re specifically designed to bring and hold together pieces of wood. Wood screws are typically thick and made of soft, snap-resistant metal.
The shank on a wood screw serves two purposes. First, when the shank enters the wood, the screw stops spinning, creating tension between the threaded body and the head without breaking the wood. This tension ensures a strong connection between the planks. The shank also helps prevent the screw from heating up from the friction of drilling.
Lag screws are traditional screws used for heavy-duty projects, and they typically require more effort to install. They are ideal for applications where several heavy objects need to be joined together. Lag screws were originally used to fasten lags, or staves, to barrels, and they can support heavier loads than the average wood screw.
Lag screws are long and thick, with the head of the screw being thicker than the threads. To install a lag screw, you have to predrill a hole for the threading and then another opening to clear the shank.
These screws are readily available and easy to find, and they’re one of the strongest types of wood screws on the market.
Structural screws are a recently introduced option that replaces thicker traditional screws. These fasteners are long, thin and sharp so they can pierce any material with ease. They come in three head styles, including the typical hex head, Torx drive (six contact points) and Spider head (eight contact points).
These screws are made from high-quality, heat-treated steel and meet numerous engineering standards. Additionally, their long, thin construction eliminates the need for predrilling, which can cut down on installation time. However, they are priced somewhat higher than other screws because of these features.
Find Your Screws With All Points Fasteners
We offer a wide variety of screws that will provide you with long-lasting fastening power, including numerous sizes, head shapes and colors to serve diverse applications in virtually any industry.
How Does a Screw Work?
The world of screws is vast, and you’ll find no shortage of different options when you shop for screws for your next project. How does a screw work, exactly, and what are different types of screws used for? Here’s a primer on the different types of screws available to you, as well as some key information as you evaluate what types of screws will work best to meet your needs.
What Is a Screw Used For?
Screws are fasteners for all sorts of construction projects, large and small. The reason there are so many different types of screws is that there are so many different ways objects and materials need to be fastened.
Sometimes screws are classified by the material they are used to fasten. For example, you might find you need concrete screws for fastening objects to concrete, wood screws for fastening objects to wood, or drywall screws for fastening objects to drywall. No one screw or fastening could possibly serve as a one-size-fits-all solution, because there are simply too many different needs and applications for screws and fasteners.
What Are the Different Types of Screws?
Because of how many different ways there are to use screws, you’ll find there are tons of different types of screws. Here are just a few of the different kinds you’ll find when searching for the right solution:
- Sheet Metal
This is just a few of the different types of screws. You may find that the screw you need is classified into one of the categories above, but it’s also categorized by its drive type (Phillips, slotted, combination, star, etc.) or by the shape of its head (oval, flat, button, round, pan, etc.). In some cases, you may find a screw is classified by a combination of terms. For example, you might find that you need a slotted flathead metal screw.
What Is the Difference Between a Self-Tapping Screw and a Normal Screw?
With most screws, you’ll need to drill a pilot hole that creates threads and helps guide the screw into a secure spot. That’s not the case with self-tapping (or self-drilling) screws. When you choose self-tapping screws, there’s no need for a pilot hole. The screw creates its own threads as it is installed.
What’s the benefit of self-tapping screws? They save tons of time when you’re working on a significant project. For example, if you’re working to fasten objects and you need to use several dozen screws to get the job done, choosing self-tapping screws can significantly decrease the amount of time the project takes you. This is incredibly important in large construction projects where getting the project done on time is of the utmost importance.
Get the Screws You Need at All Points Fasteners
At All Points Fasteners, we work each day with service contractors to ensure they have the screws they need to deliver outstanding results. We specialize in tracking down even the most difficult-to-find fastening solutions — so our clients always have access to exactly what they need.
You find nothing but products of the highest quality in our selection, as well as affordable pricing that helps your project stay under budget.
Browse our vast selection of screws.
Different Types of Screw Threads and Terminology
From professional contractors to the DIYers at home, virtually every individual performing a construction, remodeling or decorating project will use screws and fasteners. These small tools come in many shapes and sizes, typically labeled using terminology that the average homeowner or novice repair servicer may not be familiar with.
At All Points Fasteners, we understand that learning and memorizing the different types of screw threads can be confusing. To help you identify the type and use of various screws, we’ve created this helpful screw thread terminology guide that you can quickly reference any time you need to select a specific screw and screw thread measurement.
What Are the Different Types of Threads on Screws?
If you’ve ever felt lost walking down the fastener aisle of the hardware store, you’re not alone. The types of screws you need for a woodworking project like building a table are different from the screw types and sizes you would use when building a deck. Refer to our list of the different types of screws to help you identify which is the right fastener for your job:
- Woodworking: Woodworking screws are some of the most common types of screws. Used for connecting two or more wooden objects, woodworking screws feature a tapered shank with sharp threading to dig into the wood.
- Drywall: Although they can be used for woodworking, drywall screws are designed for use on drywall projects. However, the wrong-sized drywall anchor screw could damage pure plaster walls. The drywall screw size, length and weight must match the type of wall or ceiling drywall being used. Drywall screws for metal studs or hardwood, when used in cabinet work, are fine thread and twinfast which features two threads. They typically have a sharp point and a black oxide finish. When drywall screws are used in wood studs or soft woods (in cabinetry), they feature coarse threads.
- Machine: Machine screws are a common type of screw used in machining applications to connect two or more metal objects. They fit in with corresponding nuts or tapped holes that have the same diameter and number of threads.
- Lag: Also known as coach screws, a lab screw is a type of screw that forms its own thread in pre-drilled holes and is usually used to fasten metal to wood.
- Gutters and siding: Screws used for gutters and siding are designed to provide a stronger hold, typically coated with a weather-resistant material and available in finishes to match the gutter or siding color.
- Security: Security screws are unique in that they do not have an operable head like other screws, which protects them from being removed or tampered with. To install or remove these screws, special tools are required.
- Self-drilling: Self-drilling screws are available as “magnetic” and “non-magnetic” stainless steel varieties that are used for metal-to-metal and wood-to-metal applications. Roofing screws are an example of self-drilling screws.
- Self-piercing: Self-piercing screws have powerful penetration capabilities because their threads are machined down to the end of the point. They can require fewer tools and help with faster installation.
- Self-tapping: Self-tapping screws are threaded to create their own holes when installed. They form a matching thread in whatever material they are installed into. Self-tapping screws like sheet metal screws may be used in HVAC applications. Self-tapping deck screws are often coated with a corrosive-resistant material, such as ceramic.
- Thread-forming: Used with plastic materials, thread-forming screws feature two separate threads: one high and one low. This makes the pullout strength higher while also ensuring plastic does not crack or otherwise break.
- Type U: Type U screws have a unique spiral thread, and they are typically fastened into a plastic or metal casing material via a hammer instead of a screwdriver.
If you still have questions about which type of screw you need, our expert staff is ready to help you match the screw to the project.
What Is a Screw Thread?
The thread of a screw is the helical shape that runs around the cylinder of the screw. It converts rotational movement into linear movement and can include a variety of differences, like the shape of the thread, its angle and the size of the pitch — the space between the crests of each thread. Each of these subtle and small characteristics can make a significant difference in the performance of the screw and its applications.
Screw Thread Terminology
Knowing the different screw types and sizes is helpful, but to accurately select the right screw for your project, you’ll likely need to know a little about how screw threads work, as well. So, how do screw threads work? Like the screws themselves, screw threads are designed to meet the needs of specific applications.
You can try to find a screw thread chart that outlines all of your different options, but what you really need is a guide to screw thread terminology that answers all your questions and provides a comprehensive rundown of different screw and bolt thread types and why they matter.
To help you make the best investments in fasteners for your next project, here’s a thorough guide to screw thread terminology:
- External Threads: External threads (ie: male threads) mean the threads are on the bolts or screws. Threads are sometimes on the nuts rather than the bolts or screws.
- Internal Threads: Internal threads (ie: female threads) mean the threads are on the nuts rather than the bolts or screws.
- Machine Screw Threads: Machine screw threads are unique in that they are specially designed to mate with threads on nuts or threads present in tapped holes. Not self-tapping threads.
- Spaced Threads: Spaced threads are designed to form their own threads in pre-drilled holes. You’ll most often find spaced threads on self-tapping, wood and coach screws.
- Lag Screws: Lag screws are just one example of screws that form their own thread in pre-drilled holes. Typically, coach screws are used to fasten metal to wood.
- Self-Tapping Screws: Self-tapping screws are threaded to create their own holes when installed. They form a matching thread in whatever material they are installed into. This makes using self-tapping screws incredibly efficient.
- Thread-Forming Screws: Used with plastic materials, thread-forming screws feature two separate threads: one high and one low. This makes the pullout strength higher while also ensuring plastic does not crack or otherwise break.
- Type U Screws: Type U screws include an unusual spiral thread that is most often driven with a hammer into materials like plastic and metal casings.
- Wood Screws: Wood screws feature a tapered shank with sharp threading.
Additional Fastener Terminology
Here are a few additional terms related screws and threading that are helpful to know:
- Major Diameter: This refers to the diameter of a screw including the raised helix’s height like an imaginary cylinder around the thread. It is measured using a slot gauge or a caliper rule. You can only measure major diameter with an external thread screw
- Minor Diameter: Minor diameter is a screw’s diameter measured at the base or root of the thread at the innermost part of the screw. You need specialized equipment to measure the minor diameter accurately.
- Effective Diameter: The effective diameter is essentially the average of the major and minor diameters. It is measured halfway up the raised helix, and, again, you need specialized equipment to get an accurate sense of a screw’s effective diameter.
- Pitch: The pitch is the distance between two threads on the same screw.
- Crest: The crest is the height of an external thread. Or, you can find the crest by subtracting minor diameter from major diameter. The crest is the difference between the two.
- Thread angles: The thread angle is the actual angle of both flanks of a screw. Symmetrical threads indicate that both sides of the thread are angled to the same degree. It’s common for thread angles to be referred to as simply “the flank.”
- Coarse and fine threads: The terms “coarse” and “fine” refer to the distance between the crest of each thread. Smaller gaps create fine threads and larger ones create coarse threads.
At All Points Fasteners, we offer an unmatched selection of different types of screw thread options, as well as different types of screw heads and other features. We often work with service contractors in the HVAC and gutter industries, as well as do-it-yourself enthusiasts who want to achieve professional-grade results with their projects. No matter why you need different types of screw threads, we want to offer access to the type of screw you’re looking for.
Why It’s Important to Get the Right Screw Thread
Not all screw threads are going to work with all applications. Each one is tailored to different tasks and different material sizes. Some will require pre-drilled holes while others have sharp designs meant for drilling directly into softer materials like wood. Other screws vary in thread spacing, which is important for various characteristics of the screw. If using any bolts or nuts, you’ll need to make sure they match the screw’s spacing.
By paying special attention to these characteristics, you can more readily ensure that your choice of screw provides appropriate strength and performance for the application.
Free High-Quality Fastener Samples From All Points Fasteners
Using our quick reference guide, you can effortlessly determine which screw thread is right for your application. If you’re still uncertain about which screw is right for you, we encourage you to request a free sample of our stocked items or reach out to us and talk with an expert. We’re ready to go above and beyond to help your source the exact fasteners you need for your project. Browse our site today to discover the best high-quality fasteners in the industry and visit our blog for more helpful advice Call All Points Fasteners today to speak with a knowledgeable staff member who will be happy to answer all your questions.
Concrete Screws Guide
Many improvement and construction projects involve nailing or screwing into concrete. Common situations include:
- Affixing sole plates to concrete floors.
- Attaching metal conduit to a concrete surface.
- Fastening steel post anchors to concrete patios.
- Attaching shelf brackets to concrete walls.
If you’re like some DIYers and contractors, you find using concrete screws to be frustrating and difficult. However, when equipped with the right tools, fasteners and tips provided in this article, you can employ this useful fastener with ease and confidence. Learn more about how to put screws into concrete below.
How to Use Concrete Screws
Concrete screws provide one of the easiest ways to fasten fixtures to concrete, and unlike many other types of fasteners, you don’t need a shield or anchor for installation. You also don’t have to do any hammering. All it involves is drilling a hole, cleaning the hole and driving the screw in — which is why these fasteners are referred to as self-tapping concrete screws.
Concrete screw fasteners, known commonly as Tapcons, look similar to wood screws but have high-low threads, which bite the hole’s side tightly. They’re available in 3/16- and 1/4-inch diameters and in lengths as long as 3 3/4 inches. You can choose between Phillips- and hex-head styles and use them on various surfaces, including concrete block, poured concrete, brick and the mortar joints between the block and brick.
Here are some important considerations to keep in mind when drilling your concrete screws:
- Base materials: Harder base materials require less embedment to achieve satisfactory holding values. For Tapcon concrete screws, the allowable embedment ranges from 1 to 1 3/4 inches. The screw’s holding values depend on the base material’s quality.
- Hole diameter: The diameter of the hole is critical when using Tapcons. The tolerance between the diameters of the Tapcon and the hole is extremely tight, and any variation will impact the holding values. Concrete screws of a certain diameter must be installed using a carbide drill bit with a specific diameter. If you want to use screws with a 3/16-inch diameter, you must drill a 5/32-inch hole, and if you want to use 1/4-inch screws, you’ll need to drill a 3/16-inch hole.
- Hole depth: The depth of the hole in which a Tapcon will be inserted is also important. You must drill the hole 1/4-inch deeper than your concrete screw must fit. This additional space allows the dust created during tapping to fall out without affecting the installation. If you don’t create sufficient space when drilling, dust may fill the space and the screw may bottom out, preventing proper installation. This situation could also cause the screw to become stuck in the hole, preventing you from removing it or inserting it deeper.
- Screw length: The screw’s length is also important. The necessary length will depend on how thick the fastened material is. A Tapcon’s embedment must be at least 1 inch but no greater than 1 3/4 inches. To figure out the required length of a screw for your application, add 1 inch to whatever the length of the material you want to fasten is. To determine the maximum length of a screw, add the material’s thickness plus 1 and 3/4 inches. Any screw within those numbers should work for your application.
- Tapcon screw lengths: You should measure flathead Tapcons as an overall length since they’re countersunk, meaning the screw’s entire length will be countersunk into the fixture and embedded in the base material. For hex-headed Tapcons, measure from under the head, as it will stay outside the fixture you’re fastening.
- Head styles: Tapcons come in two head styles — Phillips head and hex head, each of which is meant for different applications. The flathead with a 3/16-inch diameter requires a #2 Phillips screwdriver, and the flathead with a 1/4-inch diameter needs a #3 Phillips driver. Hex heads are hex washer slotted heads driven in with a nut driver. For the 3/16-inch concrete screw, the nut driver must be 1/4 inches, and for the 1/4-inch screw, the nut driver must be 5/16 inches.
- Standard vs. stainless steel: The standard Tapcon, which is blue, is suited for indoor use where moisture isn’t present. These standard Tapcons feature a blue Climaseal® coating that protects against rust. The stainless steel Tapcon features a silver Climaseal coating, which provides additional protection against rust.
How to Drill Screws Into Concrete
Once you have the correct length and type of screw and get a hammer drill with a carbide-tipped masonry bit, follow the steps below for how to screw into concrete:
- Drill the hole: With your drill and bit, drill the hole through the material you want to fasten to the concrete surface. Make sure the hole’s depth is at least 1/2-inch deeper than the measurement the screw will need to fit.
- Clean out the hole: Using compressed air, a vacuum cleaner or wire brush, clean out any dust created when you were drilling.
- Insert the screw: After aligning the hole in your fixture with the one in the base material, insert the Tapcon through the hole.
- Rotate the screw: With a drill or wrench, rotate the Tapcon until its head is tight against the fixture’s surface. Ensure the Tapcon isn’t over-torqued, which might strip the threads in the base material, causing the screw to spin.
Our Concrete Screw Options
All Points Fasteners offers dependable, strong and durable concrete screws at an affordable price. A wide variety of service professionals — including HVAC, roofing and gutter contractors — come to us for our vast selection of concrete screws and other fastening options.
Our concrete screw selection includes both hex washer heads and Phillips flatheads and is available in quantities ranging from 500 to 8,000. All boxes include one masonry drill bit for drilling the right-sized hole.
Come to All Points Fasteners for All Your Concrete Screw Needs
At All Points Fasteners, you get more than just high-quality products at reasonable prices — you also get a customer service team devoted to helping you find the best fastener for your application. If you’re having trouble securing materials, we will track them down for you and provide you with as much information as you need before you begin your project. Just use the live chat feature on our website, call us at 800.483.6354 or fill out our online form.
We look forward to helping you find the perfect concrete screws for your project!