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Wood Screw Size Chart – What are They?

If you are in the woodworking industry, you must know the importance of choosing the right screw for the job and how it can affect the rigidity of the structure as well as the cost of the overall project. Going with the wrong screw size will not only make the job highly unreliable and compromise its load capacity, but it may also end up increasing the raw material cost considering such projects won’t see the end of the production lineup at all. Therefore, you need to be very careful when you are choosing the set of screws that you are going to need for your job before you start working on it.

Fortunately, it is much easier now to get the perfect size screws since there are a large number of options available on the market which were not available before. Now, you get to choose the perfect size screw which will not only fit well with your project but also help you cut down on the production cost without compromising the integrity of the project. Choosing the perfect set of screws also helps you to reduce additional expenses on basic projects which do not need a very durable structure, to begin with.

To help you find the perfect screw for your job, we are here with this guide for the wood screw sizes. In this guide, we will thoroughly cover the terminology of a wood screw and also offer you comprehensive information about various sizes that you can find on the market right now for a wood screw. But before that, let us first take a look at what a wood screw is and how it differs from alternate wood-joining processes in the industry.

What is a Wood Screw?

As is apparent from the name itself, a wood screw is a special type of screw that is designed to work with wood. It typically has a pointed end like any regular screw along with a threaded shaft, which allows it to be driven into wood with a screwdriver or drill.

These screws can easily attach two or more pieces of wood together at different angles allowing craftsmen to create various types of wooden joints with ease. As you can imagine, it makes working with wooden jobs much easier compared to alternative options which are simply not as reliable.

One can also use wood screws to attach hardware to a wooden workpiece such as hinges or handles, making it one of the prime requirements for almost every wooden project. They come in a variety of sizes and styles, including flat head, round head, and pan head, and can be made from a range of materials, such as steel, brass, and stainless steel. Some wood screws also feature special coatings or finishes that help to protect them from corrosion or improve their appearance.

What are the Parts of a Wood Screw?

Now that you know what a wood screw is, let us dive deep into the anatomy of the unit and try to understand the various different parts of the screw and how these parts affect the strength and durability of the screw. In the end, you are not only buying a single screw, but an entire set for your job. So a drawback on any of these factors will affect your application significantly, and might even lead to early failure due to constant fatigue and creep. Therefore, you should carefully understand the terminology of a weed screw and understand the importance of each and every aspect such as the head, shank, threads, etc.

1. Head

The head of a wood screw is the top part of the screw which is designed to be accessed by the screwdriver or a drill. The shape of the head can vary depending on the type of screw and its intended use. So, you will find many different types of wood screws on the market with varying head designs such as flat head, pan head, round head, oval head, etc. And as you might have guessed already, each design type has its own set of advantages and limitations, limiting its application to a particular set of jobs.

For instance, a flat head screw is ideal for countersinking, while a pan head screw has a rounded top and is suitable for general-purpose applications. Round head screws also have a domed top whereas oval head screws have an elliptical shape. The choice of head type is typically based on the project’s specific requirements. A great example of that would be flat head screws vs pan head screws as a flat head screw may have a countersunk head that is 82 degrees, while a pan head screw may have a rounded head that is 100 degrees.

2. Shank

The shank is the long, threaded part of the screw which is inserted into the wood. The threads are designed to grip the wood and hold the screw in its place, making it one of the most important features of the screw. The shank diameter can vary depending on the type of screw and the type of job you are using it for. Screws with thicker shanks will offer greater strength and are better suited for heavy-duty applications. There are many underlying features of the shank of the screw which should not be overlooked such as its diameter and length.

The diameter of the shank is typically specified in inches or millimeters, varying from manufacturer to manufacturer. The shank terminology is also important to know before you finalize the set of screws for your job since it can also affect your job quality. For example, a 1/4 inch diameter screw may be available in lengths ranging from 1 inch to 6 inches whereas other diameter choices may not offer a similarly wide range of options.

3. Thread

The threads are the grooves that run along the length of the shank and are the most important aspect of any screw. The screws also vary based on thread parameters, making them ideal for a typical application. For example, screws with coarse threads have greater holding power and are better suited for softwood.

On the other hand, fine threaded screws are highly preferred for hardwood. Apart from that, the thread pitch is also one of its important features which is basically the distance between each successive thread on the screw.

Screws with a high thread pitch have less friction and are easier to install, while screws with a low thread pitch have greater holding power, but are a hassle to work with, especially if you are planning to apply a hundred of these screws on your job.

Apart from the thread pitch, thread depth to get a better idea about the strength of the screw. The thread depth is the distance that the threads penetrate into the wood, and is typically specified as a percentage of the shank diameter.

4. Tip

The tip of a wood screw is the pointed end that is used to penetrate the wood. It is an important part of the screw because it is responsible for initiating the hole and guiding the screw into the wood. The tip of a wood screw is important because it determines how the screw will penetrate the wood. A sharp tip will allow the screw to easily enter the wood, while a dull or blunt tip will require more force to penetrate. The tip also determines the size and shape of the hole that the screw will create, which can affect the strength and stability of the joint.

The tip also has some technical features which play an important role in the application such as its shape, angle, and length. While a sharp tip screw is preferred for most applications, some jobs may benefit from a blunt screw, especially if the workpiece is prone to cracks.

The angle of the tip is typically specified in degrees and can range from 23 degrees for a sharp point to 45 degrees for a blunt point. For soft woods such as pine, a sharp tip is usually preferred because it requires less force and creates a smaller hole. For hardwoods such as oak, a blunt tip may be preferred because it can help prevent splitting.

What are the Different Sizes of a Wood Screw?

So far, we have discussed all of the important features that you would want to know before buying a large set of wood screws. So, you cannot easily tell which option is going to be the right one for your job. But, all that information would be fruitless unless you have a record of all the available options on the market right now. With this information, you can easily compare all of the available options at once and choose the perfect option without much effort.

So, we have prepared this helpful chart of the different sizes available on the market right now for a wood screw. So, we will strongly recommend you check out this list before moving on with your choice. Here, we are going to compare available options for Phillips flat head, round head, and oval head screws based on the ASME B18.6.1 standardization.

Phillips Flat Head Screws

Phillips Driver Size Max. Head Diameter Min. Head Diameter Head Height Max. Width of Slot Min. Width of Slot Max. Depth of Slot Min. Depth of Slot
1 .172 .147 .051 .031 .023 .023 .015
1 .199 .141 .059 .035 .027 .027 .017
1 .225 .195 .067 .039 .031 .030 .020
2 .252 .220 .075 .043 .035 .034 .022
2 .279 .244 .083 .048 .039 .038 .024
2 .305 .268 .091 .048 .039 .041 .027
2 .332 .292 .100 .054 .045 .045 .029
2 .358 .316 .108 .054 .045 .049 .032
3 .385 .340 .116 .060 .050 .053 .034
3 .438 .389 .132 .067 .056 .060 .039
3 .507 .452 .153 .075 .064 .070 .046
3 .544 .485 .164 .075 .064 .075 .049

Round Head

Phillips Driver Size Max. Head Diameter Min. head Diameter Max. Head Height Min.

Head Height

Max. Width of Slot Min. Width of Slot Max. Depth of Slot Min. Depth of Slot
1 .162 .146 .069 .059 .031 .023 .048 .037
2 .211 .193 .086 .075 .039 .031 .058 .044
2 .236 .217 .095 .083 .043 .035 .063 .047
2 .260 .240 .103 .091 .048 .039 .068 .051
2 .285 .264 .111 .099 .048 .039 .072 .055
2 .309 .287 .120 .107 .054 .045 .077 .058
2 .334 .311 .128 .115 .054 .045 .082 .062
2 .359 .334 .137 .123 .060 .050 .087 .065
3 .408 .382 .153 .139 .067 .056 .096 .073
3 .457 .429 .170 .155 .075 .064 .106 .080

Oval Head Screws

Phillips Driver Size Max. Head Diameter Min. Head Diameter Max Head Height Min Head Height Max. Width of Slot Min. Width of Slot Max. Depth of Slot Min. Depth of Slot
1 .225 .195 .067 .104 .084 .039 .031 .059
2 .252 .220 .075 .116 .095 .043 .035 .067
2 .279 .244 .083 .128 .105 .048 .039 .074
2 .332 .292 .100 .152 .126 .054 .045 .088
2 .358 .316 .108 .164 .137 .054 .045 .095
3 .385 .340 .116 .176 .148 .060 .050 .103
3 .438 .389 .132 .200 .169 .067 .056 .117


We hope that you can now easily pick out the best set of wood screws for your job based on the information provided here. In this guide, we have covered the entire anatomy of a wood screw along with a detailed comparison of sizes between the 3 more popular options for a wood screw which are Philips flat head, round head, and oval head screws. So, you can now easily compare these parameters and find the right option for your job without needing to spend any more time on the research. However, we will still suggest double-checking the specifications and manufacturer’s instructions provided on the resell packaging before you make the choice, just to be on the safe side. And if you have any doubts about the information provided here, you can reach us via the comment section, and we will try to clear your doubt as soon as possible.

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