Wood Screws – Guide, Types, Uses and Standards

Wood Screws – Guide, Types, Uses and Standards

In the market, there are different types of screws that we use. For different kinds of materials, they developed different kinds of screw types. One of these screw types is wood screws. You can find detailed information here about them. These are the general topics that we covered here;

  • What is a wood screw?
  • What are their types of them?
  • What are their uses of them?
  • Wood screw standard notations.
  • Advantages and disadvantages of them.
  • FAQs about them.

What are the Wood Screws?

Brass wood screws.
Image Source: Pixnio.

Wood screws are the special screws that we can use the wood applications. The main difference between these screws is, that they apply to wood material without harming the parts. And the threads, heads, and materials are special for these applications.

The main difference between the wood screws is the material. The material of them is quite different from ordinary screws. Because ordinary screws are for penetrating or holding steel or metal parts. But in wooden parts, we require some different characteristics such as corrosion resistance. Moisture is one of the biggest problems with wooden parts and applications.

So, brass, bronze, and aluminum materials are very common in these applications. These materials also have very good structural capabilities. And also, they possess very good corrosion resistance.

In the screw industry and screw types, the structural parameters are; screw head, screw tip, screw shaft, and screw threads. These four parameters are the most important structural things for the different operations of wood screws.

Wood Screw Tips

Also, you need to consider the type of tip of your screws. So, you can buy according to your need.

  • Self-Drilling Wood Screws: They are the most common ones. If you do not want to drill a hole before the application of a screw, you can use a self-drilling one. These wood screws have a different tip design that drills its hole in the screwing application.
  • Flat-Tips: These are other types of tips of them. You can use the flat tip wood screws if you want to create a hole before application of them. The main advantage of these screws, it is safer to apply the screws before applying them. Because is a self-drilling application, a crack may occur in the wood parts.

Wood Screw Shank

The shank section of wood screws is the section that has no threads on it. This is the main point that carries a load. Also, this shank section gives extra length to the screw. To obtain stronger joints, it is better to have a shank section of screws.

Types of Threads

Also, threads are different according to the application of the wood screw. We use different kinds of threads.

  • Hardwood: In hardwood applications, the number of threads per inch for wood screws is much higher than usual. So, it provides a better attachment between the wood and the screw. Because there is more contact area that causes better attachment.
  • Softwood: In softwood threads, the number of threads is lower than usual. So, they are very common in soft applications. And the contact forces of these threads are immediateç

Types of Wood Screws

In the industry, there are different kinds of the are available. W generally classify these screws according to their head types and drive types.

Head Types of Wood Screws

According to their application of them, there are different kinds of head standards are available.

Pan Head Types

These are the most common types of wood screws. In pan head types, the top structure of the head is in the form of a semi-sphere. And also, the bottom side of the head is flat.

These types are very common in sheet metal attachment applications to woods. Because they are very useful in holding sheet metal pieces tight on the wooden parts. Also, you need to have a counterbore hole on the wooden parts to apply these screws.

The flatness of the bottom side of the pan head provides extra safety for any disassembling. So the contact surface between the part and the pan head provides extra mechanical stability to the assembly.

Trim Head and Bugle Head Screws

They are the special head geometries of them for efficient tightness on the wooden parts. The trim head type is one of the best ones to apply to the hardest wood materials such as rosewood and ebony. Also, the other important advantage of the trim head ones, there are no protrusions on the surface of the woods. The top of the head is on the same level as the surface.

Flat Head Wood Screws

Flat head wood screws.

Flat head wood screws are also very common in wooden projects. They are best for the attachment of the wooden parts to each other.

The top side of the screw head is flat and this flatness provides a smooth surface on the parts. Because there are no protrusions on the surface. This is a much better design consideration for these projects.

Also if we take a look at the bottom side of the flat head types, you can see the conical shape. This conical shape is best for the countersink holes.

We need to state that wood screws can create their holes with the application of a screwdriver on wooden parts.

Washer Head Screws

Washers are very important mechanical parts to spread the assembly force to the wider area in the assembly section. Also, it provides much more friction between the surface and the washer to prevent dismantling.

And there are wood screws that have their washers. So, they are very useful in delicate wooden parts. And these types provide better assembly.

It will be better to use washer head screws on the plywoods. And also, it is better to have a pre-drilled hole for the applications of these types of screws.

Truss Head Wood Screws

The truss head type has bigger heads and they are like mushrooms. They are like pan head screws but the contact area between the bottom of the screw and the wooden part is much higher. So, this extra contact surface provides better attachment.

These are the general head types of wood screws. As you understand, the head type is a very important parameter in the different kinds of applications. So you need to consider the type of head that you want to use for your wood applications.

Drive Types of Wood Screws

Above all, the drive type of these screws is very important also. There are different types of drives for screws and they affect the working efficiencies in different applications. You need to be considerate about drive types also.

With the changing drive types, the drill bit shapes are also affected. If you are producing a common wooden application that will be dismantled by users, it is very important to use one of the most common types of drive. Let’s check the drive types of wood screws.

Drive types.

Straight Drive Type

This is one of the most common types of drive-in wood screws. There is a straight recess on the head of the screw. And you can easily dismantle and mantle these screw drives by using straight screwdrivers or drive bits.

Philips Types

These drive types are also very common in the wood screw industry. The general shape of these types is “X” on the head of the screw. You can easily attach X-type drive bits or screwdrivers to attach or detach these screws.

Also, the screwdrivers and drive bits are the most common ones. So, you can use these Philips types in your different applications or common applications that people will use.

Hex Wood Screw Drive

Hex screw drives are also very useful in wood screw applications. We need to use Allen keys for dismantling these kinds of screws. Also, torque applications are somewhat high in the hex drives. And, the attachment of the hex Allen key is much easier.

Torx Screw Types

At the top of the head, there is a six-point star design screw drive on these wood screws. So, it provides better engagement between the tool and the screw. And this provides safer working. But, high torque applications are not common in these applications. So, Torx screw applications are not common.

Furthermore, the drive bits and the screwdrivers are not common among people. This means that it is better to use other common types of drives for wood screws.

Security T Drive

These drives are very special in design. Because it provides extra security in these applications. There is a shape on the head of the screw which resembles Torx screws. But also, there is a protrusion. So, you need to have a special tool to dismantle these kinds of wood screws.

Also, you can not detach these screws with other kinds of screw drives. Because you can not attach it to this shape. The Security term comes because of this issue. Furthermore, we are not using extra security in wooden applications generally. So, you do not need to use it.

Double Square

This drive type is also designed to provide much higher torques and attachment forces. If we take a look at the general shape of the screw drive attachment hole, there is an 8-point star. So, a very good attachment takes place between the tool and the screwdrivers.

But also, these drive types are not common. So, you do not need to use these extra specific solutions for wood screws.

Pozidriv Wood Screw Type

Pozidriv drive types resemble the Philips type. But there are extra clearances between the X. So, so these extra clearances provide extra torque application and extra attachment between the screwdriver and the wood screw.

Also, this is not a common application in these screws. If you are making a common application, you do not need to use solutions that provide extra torque or attachment.

Japanese Industrial Standard

This is another specific wood screw drive type that we did not use generally. There is an X drive at the top of the screw but also there is a little recess. So, you need to use specific screwdrivers. You do not need to use these screwdrivers in your applications.

Wood Screw Caps

Wooden applications are very common in decorative systems and decorative purposes. So, capping the screw heads in these decorative systems is a very common practice. In the market, there are different caps according to the drive type. You can attach these wood screw caps at the top of the screws.

These caps are generally in the same color as the wood applications. So, they hide the unwanted screw appearance from decorative wooden parts.

Also, there are caps that you can use to give different aesthetics. You can check the different wood screw cap designs for your applications.

You just need to place these wood screw caps on the top of the screw head. There is a socket beneath the caps that you can strictly attach to them.

General Materials of Wood Screws

Also, the type of material is very important in the selection of wood screws. We need to consider the different materials for different kinds of applications. Around these materials; are stainless steel, steel, and brass.

  • Brass: Brass wood screws are very common in decorative applications. Because their appearance is different and shiny. You can use the caps on these brass screws to obtain complete decorative wooden work. But, the mechanical strength of the brass screws is lower than the steel and stainless steel ones. So, you need to take special care in the application of them.
  • Steel: If you wish for mechanical strength and a stress-resistant system, you can select steel as a wood screw material. So, the general application of steel is very common. But the most important drawback of steel is, that it can corrode in moisture environments. So, it is better to apply them in a low moisture environment.
  • Stainless Steel: Also, if you want both mechanical strength and corrosion resistance, stainless steel wood screws are the best for you. You can use them in different applications such as high moisture environments with very high mechanical needs.

As you see above, according to the application, you can select the proper material for your screws.

Special Coatings on Wood Screws

For these screws, corrosion can be a very big problem. Because wood parts generally absorb moisture which is very harmful to the screws. So, there are different coating and plating applications on wood screws to enhance the life cycle and useability.

Zinc Plating

Zinc plating on steel screws is a very common practice in the coating of these applications. This metal provides a better appearance and very good corrosion resistance. If you will use your wooden system, it will be better to select a zinc-plated wood screw. Because ordinary steel screws can get corroded in moisture environments.

Galvanizing

Like Zinc plating, galvanizing is also very common in wood screw coating applications. So, we obtain very good corrosion resistance with the galvanizing of these wood screw systems.

Coloring Applications

To provide different kinds of colors of wood screws, generally, we use brass plating and other colors of coating methods. Because in some wooden applications, appearance is very important. You can find different colors of wood screws which are stainless steel but, different in colors.

Screw Lubrication

You can apply this yourself to wood screws. To decrease the friction between the screw and the part in the attachment, you can use lubrication liquids such as beeswax to inhibit the friction. You can have a better and safe attachment with this lubrication application.

Standards of Wood Screws

Like other machine elements, wood screws also have standards. You need to consider these standards in industrial applications. But first of all, we need to delve into some important aspects that we need to know to understand standards.

  • Major Diameter: The diameter of the shank defines the major diameter of wood screws. So, the major diameter is very important in the standards. Also, with the increasing major diameter, the total mechanical strength of the screw increases.
  • Screw Length: The total length of the wood screw is also a very important parameter. In standards, the length of the screw is a very important parameter. We need to specify its length. And also, you need to consider the length of the screw in your applications.
  • Thread Pitch: Also, the pitch of a screw is a very important parameter in the standards. Because it gives an idea about how many screw threads per inch length of the screw. This value also defines if it is hardwood or softwood thread.

American National Standard Wood Screws

In the American market, there are different types of screws available. The general lengths and dimensions of these screws are made according to the standards.

American Flat Type Wood Screw

American flat types wood screw.
Image Source: FREDERICK E. GIESECKE, SHAWNA LOCKHART, Technical Drawing With Engineering Graphics 15th Ed., Pearson, Pg.621

If you take a look at the general shape of the American flat head wood screw, the deepness of the screw clearance is 0.25 times the major diameter. And the clearance is also 0.25 times the major diameter.

And also, the length of the screw thread is 2/3 times the diameter. The angular span of the conical shape of the American flat screw is 80-82°. And also, the total diameter of the screw head is 2 times the screw diameter.

American Pan Head Wood Screw

American pan head.
Image Source: FREDERICK E. GIESECKE, SHAWNA LOCKHART, Technical Drawing With Engineering Graphics 15th Ed., Pearson, Pg.621

If we take a look at the screw; the thread length is the same as the flat type one. And also, the deepness of the drive clearance is 1/3 times the major diameter of the wood screw. And also, the clearance is 0.25 times the major diameter.

These are the standard dimensions of American pan head screw types.

American Oval Head Wood Screws

American oval head.
Image Source: FREDERICK E. GIESECKE, SHAWNA LOCKHART, Technical Drawing With Engineering Graphics 15th Ed., Pearson, Pg.621

This is another important type of standard American wood screw. If you take a look at the general structure of the oval head type, the drive clearance deepness is the same as the pan head type. Also, the thread length is the same as other types. And the drive clearance is the same as the pan head type.

And also the angular span of the screw head is the same as the flat type. The total head length is also the same with flat type wood screw. So, you can think of it as a mix of the flat head and pan head types of screws.

Standard Numbering and Notation of Them

In a technical drawing or on a box of wood screws, you may see some numbers. It is very important to know the general meanings of these numbers. Let’s check the example;

  • .5 x 2/3 PAN HEAD WOOD SCREW

You can see these notations on technical drawings. This is a very common notation also at the boxes of the screws. The meaning is very simple.

.5 is the major diameter of the screw. This is generally in inches. Also, 2/3 is the total length of the wood screw in inches. PAN HEAD WOOD SCREW gives the type of the screw also. So, it is very simple as that.

Uses and Applications of Wood Screws

According to the information above about wood screws, there are different kinds of applications for them. As you may think, most of the applications are wood applications. But there, we mention the specific applications of these screws.

Decorative Applications

Decorative applications.

Decorative wooden applications are very common in our homes and offices. You can see lots of kinds of furniture that are made from wood. If you take a closer look at these objects, you can see the wood screws are attached to the assembly sections of the wooden sections.

Also, there are caps on these screws to hide their shiny image. So, you may see them as single objects.

The most common wood screw type in decorative applications are small steel screws or brass screws. Because decorative applications will not expose any moisture. And corrosion and rusting probably will not be a problem. Also, they do not need any extra mechanical strength. So, steel and brass screws will be sufficient for decorative wooden applications.

Outdoor Structural Applications

Outdoor applications of wood screws.

Also, you can see lots of kinds of outdoor applications of wood parts. Especially, small house applications of woods are very common. And we use them in the attachment and assembly of the parts to obtain these outdoor structures.

In outdoor environments, the screw will expose moisture heavily. And also, we need extra structural support from the screws. So, it will be better to use stainless steel screws. Because stainless steel wood screws will have very good mechanical strength and rusting ad corrosion resistance.

Covering Applications with Plywoods

We generally use plywoods in different kinds of covering applications of objects. In these applications, we can use steel and steel self-drill types. Because we generally do not expect any structural strength from these systems. Also, we do not have any decorative purpose in these applications. So, it will be very sufficient to use the cheapest screws.

Carpentry

All the applications are applied in carpentry applications. In carpentry, experts are producing nearly all kinds of wooden products from different kinds of woods. So, they have all the types of wood screws in their workplace.

You can bring much more deep information from carpenters about the screws and their uses.

Advantages and Disadvantages of Wood Screws

Like the other machine elements, there are different advantages and disadvantages of wood screws. You need to consider all of these advantages and disadvantages while you are applying them in your wood applications.

Advantages

  • The most important advantage of the screws, they are very proper for wooden applications. Their special design prevents any cracks or other structural problems with woods.
  • Also, they are cheaper than the other kinds of screws. Because the wooden applications generally do not require extra mechanical strnegth. So, the general structures and materials of screws are cheaper than the other ones.
  • There is a wide variety of wood screws that we can use in different kinds of wood applications. Also, different wood materials have different features. In the market, you can find the best screw for your specific wood applications every time.
  • The application and the attachments of these screws are also very easy. Their special design provides smooth and easy driving through the wood materials.

Disadvantages

  • The most important disadvantage of screws, we can not use them in other structural applications with other materials. Because they are specially produced for wood applications. We need to use them only in the woods.
  • Getting rusted with moisture can be a problematic issue. Because the rust is also very harmful to the wood itself. These special wood screws prevent rust, unlike stainless steel ones. You can have these if your wood application will expose to moisture.
  • You probably can not find all the head types in the market. Because some of the head types are not common as straight or X types. Because we use these screws in common wood applications. Wood applications are generally daily applications. There are nearly no industrial applications of wood materials.

Conclusion

As you understand, screws are very common in different kinds of applications. Because of that, there are different kinds of wood screws that we have in the market. We can select one of them according to our applications.

Also, there are different types of heads. These are generally according to the standards. We need to consider the types of the head in the selection of a proper one.

And also, drive types of screws are a very important thing. It changes according to the application type. It is very important to use the most common ones in general applications.

Materials and coatings of them also affect their general use of them. For example in indoor applications, steel can be sufficient. But outdoor applications, you need to use stainless steel wood screws.

It is also very important to know the general standards and notations about them. Because you need to select one of them professionally. And you need to use these standards while you are drawing technical drawings.

Like other machine elements, these screws also have advantages and disadvantages. We need to consider them.

Above all, do not forget to leave your comments and questions below about the wood screws.

Your precious feedbacks are very important to us!

FAQs About Wood Screws

What kinds of screws are best for wood?

The best screws for woods are wood screws. Their special design and materials make them proper for different kinds of wood applications. So, you need to specially search for these screws if you want to use them in wood applications.

How are wood screws different? 

The most important difference between these screws, the length of the threads is smaller than the usual screws. Also, there are differences in materials such as brass is the most common material that we use in decorative wood applications.

What type of wood screws are there?

Their types are changing according to their use. The general types are; pan head, trim head, washer head, flat head, and truss head. So, the classification and the types of screws are generally made according to the type of head.

Can you screw it into the wood without a drill?

Yes, you can. There are wood screws that have self-drill tips. You can use these types of screws to drill the wood by screwing them. So, it is possible to do it.

How do you tell if a screw is a wood screw?

The most common difference between them from other ones is their thread spacings. Their threads are spaced more scattered. Also, you can spot a wood screw from its material. The decorative ones are generally brass.

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