Screws come in a variety of shapes and sizes. We went deep and conducted extensive research to compile this categorized and well-organized screw buying guide, which lists and illustrates every type of screw-head available for each job, material, and application.
There are many distinct screws and an elaborate set of pieces that go into making a screw. We delved in and decided to write a comprehensive screw tutorial.
60 different types of screws, bolts, nuts, screw heads, and washers are shown in the Screwhead Buying Guide Chart:
Finding the proper screw head for your specific purpose can be difficult, especially for novice DIYers, as there are innumerable head shape and drive type combinations.
It’s crucial to know the distinctions between various drive types and screwhead shapes, not just because you can get the correct tools for the screws you’re using but also so you can make sure your screwhead performs what you need it to do for your project.
To begin, consider what it means for a screw to be countersunk or non-countersunk, as well as the many types of screwheads available for each.
Shapes of Screwheads
Although the shape of your screwhead may not appear to be significant, each head type is designed for a specific purpose, usually to make your project easier to complete and with your intended finish. The head of a screw is where it will come to a halt. Only the threaded portion of your project will be beneath the surface, leaving the head exposed or level with the character.
Some head forms aid in creating the final product’s appearance, but they usually have a purpose that goes beyond aesthetics.
The screw’s head shape also aids in driving the screw into your material utilizing your force and the screw’s mechanics.
Types of Screwheads
Screwheads come in a variety of shapes and sizes.
Countersinking is a technique for preventing the wood from splitting when drilling. You can use a countersinking bit to generate both a pilot hold and the right angle for your screw to be housed. The procedure pre-drills your hole with the proper head angle, resulting in a professional-looking finish. Because of their form and angle, some screwheads require countersinking. Before drilling, you’ll need to countersink the following head shapes:
Flat screwheads are completely flush with the surface, leaving no exposed head. Countersinking is required for these sorts of screws. Flat screws have the advantage of not protruding out from the surface and catching on to other objects, which is important whether you’re making your own sofa or building a bookcase that will be seen frequently. If you use a screw cover, you won’t be able to view the screw head.
Flat Head Degrees
Flat head screws come in a variety of sizes. A flat head’s degree refers to the angle between the top of the head and the surface where the threaded component meets the head. The normal flat head angle is 82 degrees, although other angles include 90 degrees, 100 degrees, and more. A greater degree necessitates a smaller but more evenly spaced countersink hole.
Flat Undercut 82-degree
The flat undercut 82-degree head angle is the same as a regular 82-degree head, but it is substantially shorter. Because of its smaller head size, this head shape allows the screw to have a larger thread on the same screw length.
Raised heads, also known as oval-shaped heads, have a similar angle to flat screws but a dome-shaped head. To accommodate the angle, you’ll also need to countersink these screws. The head of a raised screw, unlike a flat screw, will protrude somewhat from the surface. This shape is more decorative than functional, as it does not assist the screw drive performance.
Screws with bugle heads are mostly used for plasterboard and drywall. This design is similar to a flat screw head, but instead of an angle beneath the surface of the head, you’ll observe a curved shape that can help prevent surface damage. Bugle screws are basically self-drilling, which means there is no need to drill pilot holes before you use them, and their unusual form distributes stress over a larger area than flat screws.
Because non-countersunk screws have a head shape that isn’t angled and lies outside of the surface of your project, an angle to house the screw head isn’t necessary. The following are the most prevalent varieties of heads that do not require countersinking:
Binding screws are a special sort of screw that can be used for a variety of tasks. These screws feature a slightly domed head with a male and female side that screw into each other.
Short binding screws are commonly used to keep huge manuals and other bookbinding projects together, but they can also be used to hold swatches, leather, and other materials together.
One of the most popular varieties of heads is the domed head. These are great for projects where you don’t need to disguise the screw head like a flat head, like an ottoman that has protruding decorative screws.
The dome form provides an aesthetically pleasing design on the surface, while the flat inner half of the dome aids the screw in stopping right at the surface.
Frame screws are another name for flange screws. These screws have a circular or hexed head that protrudes from a circle-shaped flange just underneath the head. It serves as a washer for some designs, allowing the screw to stay in place.
These types of screw heads are wider. Their surface is a bit rounded surface than conventional screw heads. When you’re working with sheet metal or other tasks where you need larger holes, these screw heads are frequently required because the wider heads prevent the truss screw from passing through the hole.
Although these are the most common types of screw heads, many varieties and combinations are available. It’s crucial to consider whether or not the screws should be countersunk.
You can always tell by glancing at the top of the head.
A screwhead that requires countersinking has an angular shape beneath the head, whereas a screwhead that does not require countersinking has a flat shape behind the head. It’s equally important to think about your own project. Do you mind if a rounded head protrudes from the surface, or do you prefer a flat screw’s smooth finish?
A combination of screwheads may fulfill your demands, as long as you understand how each one will affect your project’s assembly and final appearance.
Types of Screwhead Drives
The type of tool you’ll need to insert the screw is referred to as the drive of a screwhead. You’ll notice that screws come in a variety of forms, in addition to their head type, that necessitate the use of a specific screwdriver.
The way the screw adheres to a surface is closely related to the drive.
Some drives are better than others at avoiding stripping, which renders a screw worthless, but they may be more expensive and harder to find tools for.
1. Hex External
The hexagonal head of external hex screws protrudes from the surface. Some have flanges built-in, whereas others have merely the hexagon form as the complete head.
To install or remove these screws, you’ll need a wrench or socket. Because you turn the entire head rather than just the interior piece of the head, you may achieve a lot of leverage with these screws.
2. Hex Internal
To install or remove an internal hex screw, you’ll need an Allen wrench. These screws are popular for furniture that requires some assembly because, unlike Phillips or slotted screws, they are unlikely to be damaged by the Allen wrench during installation, leaving you with a nice finish. An Allen wrench is included with most internal hex screws.
One of the most common screws is the Phillips screw. The cross-shape of this screw aids in self-centering, preventing it from drilling at unusual angles. A Phillips screw can also be used with a drill due to its self-centering construction, which allows it to stay in position when force is applied from a drill. Too much force, on the other hand, can swiftly strip the head.
Pozidriv screws have a similar appearance to Phillips screws, but they have a few additional grooves in them that form a star shape. A Phillips screwdriver can sometimes, but not always, be used to remove them.
When compared to Phillips screws, these screws provide slightly better rigidity when force is applied, but you’ll need a particular bit or screwdriver to fit the grooves.
When looking at a screw from the side, you can identify the difference between a Pozidrive and a Phillips screw. You’ll observe ribs between each of the four arms on the Pozidrive, and they’ll be designated with a “pz.”
A Phillips square drive, commonly known as a Quadrex head drive, is a combination of Phillips and square recess. It has a similar appearance to the Phillips design, but the middle of the cross shape is squared rather than pointed, which aid can prevent stripping when using higher force.
Because they have one narrow opening for a flat screwdriver, slotted head screws are commonly referred to as flathead screws. Although this is one of the most popular and affordable varieties of a screw, it is also the most prone to stripping. In fact, slotted screws are designed to strip by design in order to prevent overtightening. Slotted screws are ideal for jobs that require a few screws that can be screwed manually rather than with a powered drill, which can strip or cam out the screw.
7. Square Recess
Robertsons are square recess screws that are also known as square recess screws. Cam outs are prevented by the square center point.
The bit for driving square recess screws likewise protrudes on a square taper, creating a self-holding design that eliminates the need to hold the bit in place.
Star-shaped heads come in a variety of fashions, all of which are formed like stars. Two Robertson’s squares form an 8-point star in the midst of the double-square drive. You can drive it with a Robertson’s bit or a special double-square bit for higher torque applications. A 12-point star is created by combining three Robertson’s squares into a triple square.
When you require a lot of force without stripping the screw, triple squares are the way to go. They’re usually seen on interior automotive elements, such as drivetrain components.
TORX screw bits are common in drill bit sets. However, they are rarely used. TORX screws have a six-pointed star in the middle and are commonly seen on electrical devices such as computers and DVD players.
The ability to prevent cam out, which is especially useful when assembling electronics, is one of the reasons these screws have become more popular in recent years.
10. TORX Plus
The narrower grooves between the star points of TORX Plus screws allow a screwdriver or bit to make more contact with the screwhead, allowing you to apply more force.
The Phillips Screw Company’s Tri-Wing screws are a relatively new design that allows you to apply more force than a conventional Phillips screw while also providing more security than other screws.
Installing and removing the Tri-Wing design requires a specific driver, and its deep grooves allow for more torque from a drill.
If you come across a screw that looks somewhat different from the type it claims to be, it’s most likely a tamper-resistant version. Tamper-resistant screws come in a variety of shapes and sizes, including TORX, Phillips, and Hex. These screws are useful in public settings that may be targeted for theft, such as public restrooms, where pricey fixtures may lure thieves.
Tamper-resistant screws come in a variety of styles, each with different levels of security:
1. Pin Screws
The pin screw is the most popular type of tamper-resistant screw. It has the same design as conventional screws, such as a cross-shape for a Phillips screw, but with an additional layer of security to prevent easy removal.
Each head will have an additional pin in the design that must be installed and removed with a special tool. A tamper-resistant Phillips screw cannot be installed or removed with a Phillips screwdriver.
2. Sentinel Screws
Sentinel screws provide further security because they can only be driven one way. Because they’re difficult to remove, they’re best used as permanent fixtures.
3. 2-Holes Screws
2-hole screws, sometimes called spanners, provide security without losing aesthetics. They have a flat head with two small holes that must be installed and removed using a special tool.
Before you buy, there are a few more points to keep in mind concerning different screwheads:
Many screws are meant to prevent cam outs, but the slotted screw’s designers purposely designed it to cam out to prevent the screw from overtightening. Cam out is the last thing you want to happen during your assignment.
When it cams out, your screwdriver or bit will slip out of the screw head.
When this happens, it can:
- Strip a screw’s head, rendering the screw worthless
- Split the wood you’re drilling into
- Damage other materials with nicks, fissures, and other flaws.
- Endanger the user’s safety
Screws that can withstand more torque or force are less likely to come loose. Screwheads with multiple grooves, such as TORX and other star-shaped heads, provide additional points and grooves for your tools to grip, reducing the danger of a cam out.
Make sure you get the proper bit for your screw to avoid cam out.
Preventing Screw Stripping
The most important thing you can do to avoid stripping your screws is to use the correct drill bit and make sure it’s a decent one. A cheap drill bit may save you a few dollars, but it won’t help you much in the long run if it wastes all of your screws.
On the other hand, the wrong size bit could be to blame. A screw with a stripped head can be caused by a bit that is slightly too small or oversize.
It’s also critical not to position your bit so that it turns wrongly. It’s easier to avoid this with some screw heads, such as TORX, but it’s more difficult with others, such as Phillips and slotted.
Removal of Stripped Screws
If your screw heads strip off, they’ll be damaged to the point where you won’t be able to install or remove them using your ordinary tools. Do not attempt to install a screw with a stripped head. Remove the existing screw and replace it with a new one.
If the screw is completely installed, removing it can be difficult unless you have a specific tool called a stripped screw extractor. This unique bit is sometimes included in a kit with other tools that work together to grip and remove the stripped screw.
Buying Screwheads to Match Materials and Projects
It’s pointless to spend extra money on a screw and matching bit for a project that you won’t use. Small woodworking operations that don’t necessitate the use of a drill can usually be completed using a Phillips, slotted, or other simplified screw head. With any project that requires only a light force from a drill or manual use of a screwdriver, it’s a smart rule of thumb to go for a more basic design.
You’ll want a screw head with a design that includes numerous points and grooves, such as a TORX or Twi-Wing screw, for more intricate projects using heavy-duty materials, such as putting sheetrock or assembling automotive parts.
Material of the Screw Head
The material of a screw’s threaded section will nearly always match the material of the screw head. However, depending on the materials you’re working with, different materials can major impact your project.
Most screws are made of steel. However, they can also be made of stainless steel or titanium, which are more weather-resistant than standard steel. These are wonderful solutions for assembling outdoor furniture or anything else that will be exposed to the elements.
You can also come across aluminum screws, which are suitable for projects that will not be exposed to the elements. Aluminum corrodes quickly and is not as tough as steel or other heavy-duty materials.
If you’re going to use a drill to install your screws, you’ll want to use a more durable material, as aluminum can strip more quickly when subjected to higher drill force.
The majority of common screws are inexpensive. When you need screws in unusual sizes, you may notice a significant increase in their price. Also, specialty screws, such as drywall screws, are often more expensive than general-purpose screws.
In most cases, the screw head makes a difference as well. More common heads, such as slotted and Phillips, are generally less expensive, although star-shaped, TORX, and other high-performance screws may be more expensive.
They will, however, save you time and effort when assembling your project because you won’t have to worry about cam out and stripping with high-performance screws.
Where Can I Purchase Screws Online?
You now have a better understanding of the many types of screwheads and how they might help you with your project. If you’re looking to buy screws online, we propose the following stores, which have a large range of screws and heads to suit your needs:
- Home Depot