Rivets are very common mechanical fasteners. In lots of kinds of applications, we can see these permanent fasteners. Here we explain the general aspects of these fasteners. How to choose a proper one wisely and which applications that people are using them.
What is the Rivet?
A rivet is a permanent mechanical fastener that we apply by holding two metal rolls or sheet metal parts. To attach these fasteners, we drill holes to two pieces of metal and attach them inside these holes. And we apply pressure on the rivet structure to obtain permanent attachment.
They produce these fasteners according to the metal thickness. The general proportions are 1.2*√t to 1.4*√t where the “t” thickness of the metal parts.
According to the application type, the diameter of the rivets changes. For example, in single applications, the diameters of these fasteners are bigger than the multiple applications.
And also, it is a common application to make the hole diameter bigger than the rivet diameter. Generally, the hole diameter is 1.6 mm or 1/16″ bigger than the fastener shank.
How to Attach Rivets?
The attachment of these fasteners is somewhat different than screws or other types of detachable fasteners. There is a rivet machine that applies pressure on the top of the rivet after attaching it inside the hole. So, this pressure gives a cap shape to the top side of these fasteners. With this deformation, a permanent fastener application is obtained.
Also, because of this extra deformation, the shank of the rivet fills the hole which is bigger in dşameter. This is the main reason why we have a bigger hole diameter than these fasteners.
Machines or Mechanisms to Attach Rivets
There are different kinds of machinery or machines to apply the rivet applications on parts. Some of them are automatic some of them are handheld.
- Manual hammer: With a deforming bar, you can use a hammer to fit the solid and tubular rivets easily.
- Handheld squeezers: This is also a very common thing in the manual application of these fasteners. So, you can easily squeeze it like by using pliers.
- Pneumatic hammers and squeezers: Their use are common in industrial applications such as bridge or ship assemblies where very high tightening forces are required. Also, pneumatic systems are automated systems that provide better working comfort.
- Riveting machines: There are also riveting machines available that automatically attach the rivet joints in a serial production manner. They are best for the high production rates in industrial applications.
- Pin hammers: Pin hammers are special hammers to obtain riveted joints.
Types of Riveted Joints
In mechanical and structural applications, there are different kinds of riveting joints. You should not mix this with the types of these fasteners. These are the types of riveted joints in structural applications.
- Single-riveted lap joints: The lap joints are also very common in welding operations. In these types of joints, two metal parts are overlapped to each other. And one row of holes is drilled into these parts. And the application of the fasteners is made to obtain one row of joint application.
- Double-riveted lap joints: In the requirement of higher mechanical strength, there is an application of two rows of joints. The construction is the same as the single-riveted joint. So, we obtain the more strong structures.
- Single-riveted butt joints: Also, butt joints are very common in welding operations. In the butt joints, we join the edges of the two thin metal parts to each other. And we add extra two additional thin metal strips to the up and bottom side o the butt joint. And then, we apply the rivets on these three stacked butt joint metal sheets. In the single-riveted butt joints, there are two rows of a mechanical ones.
- Double-riveted butt joints: This is the double size of the single-riveted butt joints. There are four rows of these fasteners to obtain much higher mechanical strengths. We generally use these structures in bridge applications or bigger structural applications where we need very high mechanical strengths.
So, as you see above there are different kinds of attachments to the rivets.
Types of Rivets
There are various types of rivets are available in the market. So, selecting the proper one is a very hard thing. You need to give a special amount of attention to selecting the proper one for your application.
This is the most common type of fastener available in the market. In various kinds of sheet metal attachment applications, they use these types of fasteners. Also, this is one of the first rivet applications in history.
The attachment of these rivets is classical. You just need to hold the rivet gun and press the heads to obtain the two-cone cap joint.
They are very reliable and mechanically strong. For example in aircraft and structural applications, their use is very common. But today’s aerospace technologies, the use of these fasteners is not common as before.
In history, the use of high-strength steel rivet applications was common. The materials of these rivets are high strength to withstand very high mechanical loads. In the bridge and ship applications, they were using these fasteners. But, their use is replaced by bolt and nut applications. This is because the application of the steel ones requires a skilled workforce. Also, welding is another important joining technique that we use in bridge and ship applications.
This is also a very common type of rivets available in the market. The general working principle of them, there is a pulling mechanism with a rod. Once you attach this fastener to the hole and pull the rod with a mechanism, the blind side will deform to form a cap on the other side of the part. And the mandrel of the rivet forms another cap to hold two parts. After that, we cut the rod to obtain a certain fastening.
The main advantage of these fasteners, if you do not know the deepness of the sheet metal and can not see the other side, we can apply these blind rivets. We can easily apply from one side by pulling the rod to attach the rivet to the hole.
In general, there are three types of blind rivets; pull-mandrel, threaded and drive-pin types.
- Pull-mandrel types: They are the countersunk types of blind fasteners. The application of them is like the common blind rivets. But there are no protrusions on the parts.
- Threaded types: They are threaded types that they use in mechanical applications where higher force and loads are required in general.
- Drive-pin types: These are the aesthetical types of rivets that they use in architectural and decorative applications. Because there is no need for the application of extra hole drilling.
The working principles of the oscar rivets are the same as the blind types. But the main difference is, that there are three splits at the shaft. These splits are folded and deformed on the workpiece with the pulling action of the rivet application. So, it provides a better and tighter application.
Furthermore, the main advantage of these types of fasteners, they are best for high vibration applications. Because the contact surface between the workpiece and the rivet is higher than the other ones.
They are the types of rivets their application is the same as the solid ones. But the main difference is, that there is a hole at the end of these rivets. This hole and cylinder shape provides more easy deformation of the head on the part. So, the swelling and deformation do not take place for all the sections of the rivets. This provides a smaller force application if we compare it with the solid ones.
They are also very good for applications where a little movement between the parts is better. Because there is the swelling effect of the tubular rivets inside the holes.
The types of tubular rivets can change according to the deepness of the hole. So, if there is a very deep hole, we call them full hole ones. Also, there are semi-tubular types that have a hole deepness of 1.12 times the shank diameter.
In aesthetic applications where very high compression rates are not required, the use of tubular rivets is very common.
Friction Lock Rivets
Friction lock rivets are also very common in aerospace applications. Their structures are the same as the expanding bolts and solid rivets. The only difference is, that the shank geometry of these fasteners is best for the countersunk holes. So, in the application of these rivets, a swelling action occurs and very tight friction between the part and the shank takes place to hold the material.
They are the most common rivet applications in aerospace applications. Because they are for the countersink holes. There are no protrusions on the surface such as cap head etc. if you use these kinds of fasteners.
They are very good to reduce the aerodynamic drag because there is no extra protrusion that will cause drag.
They are the types of rivets where there is no need for hole drilling. The design of the tip of the rivet gives the possibility to drill the hole for itself. Also, they are very good for water-tight applications to prevent water leakages from outside.
Compression rivets are aesthetic rivets that are generally used in textile applications. To hold the two pieces, there are male and female sections. Through the holes of the workpieces, male and female sections come in contact and are applied tightly.
Split rivets are the types of rivets to use in home applications. You can use these kinds of fasteners in the application of soft materials and repair applications such as plastic and wood.
There is a two-bifurcated structure at the end side of these rivets. This provides self-piercing action on the material while you are applying. But we do not recommend using these fasteners in applications where tight applications are required.
Types of Heads in Rivet Applications
There are different types of heads in the rivet applications. These heads are important for different types of applications.
- Flathead: The head is flat in shape where the thickness of the flat protrusion on the surface is 0.33 times the diameter of the shank. Also, the diameter of the head is 2 times the diameter of the shank.
- Countersunk head: Countersunk rivet applications are very common in aerospace applications. Because there is no kind of protrusion on the surface. The total span of the countersunk head is 1.85 times the diameter of the shank. And the angular orientation is 90 degrees. The vertical deepness of the countersunk head is 0.425 timed the shank diameter.
- Button head: In the button head applications, there is a very high semi-spherical protrusion on the surface. The height of this protrusion is 0.75 times the diameter and the width is 1.75 times the diameter.
- Pan head: The roundness of the protruding cap is smaller than the button head for pan heads. The total width is 1.72 times the diameter and the total height of the protrusion is 0.57 times the diameter.
- Truss or wagon box head: The contact surface between the head and the workpiece is the biggest in this type. The diameter of the width of the head is 2.3 times the diameter of the shank. And also the height of the head is 0.33 times the diameter.
Rivet Symbols in Technical Drawings
In engineering applications, it is very important to show the rivets in technical and engineering drawings in a proper way. Here, we will give the necessary information on how to show the different types of rivets in technical drawings.
Firstly, there are two major classes to show them in technical drawings; shop rivets and field rivets.
According to the head types and sizes, we draw them in different ways.
This is the first class of rivets that we give the different symbols for them. According to the sizes, we define stems with different symbols.
- Two full heads: If the rivet has two heads on both sides of the workpiece, we show it with a plain circle like this;
- Countersunk and chipped structures: We show these structures according to the placement of the countersunk. Check the shapes below. If the countersunk head is at the outside of the workpiece which is looking at us, we show it with small lines around the circles. And if it is inside, we show these lines at the inside of the circle. If both ends of the rivets are countersunk, we draw an X on the circle.
- Countersunk up to 0.125 inches of height: In this class, we use only one line to show the symbols for three types. Also, the countersunk geometry has very little protrusion at the top of the surface.
- Flat head rivets between 0.50 to 0.625 inches of height: Also, we show the inside, outside, and both side flat surfaces with two lines parallel to each other. The flat head height is up to 0.25 inches.
- Flat head rivets between 0.75 inches of height and over: We show them with three parallel lines. Also, the height of the flatness is up to 0.375 inches.
The difference between the field rivets from the shop rivets, they do not have any protrusions on the both inside and outside surfaces of the work parts. Their explanation in engineering drawings is different.
- Two full heads: There is a straight member in the hole and there are no heads. We show them in technical drawings as a black point.
- Countersunk field rivets: Again, there are no protrusions of the rivets on the surface. We show them as black dots with one X symbol as you see below.
These are the general showing techniques of different heads and types of rivets on engineering drawings of structural parts.
There are different kinds of materials available for rivet applications for different purposes. The material is very important. Because different materials have different corrosion and wear resistances and different mechanical strengths.
Mechanical strength is the most important feature that we need to look for in rivet applications. It is because the general loading condition on these fasteners is shear stress. With the application of shear stresses, the material will tend to shear between the sheet metal parts. So, we need to make out calculations according to the biggest shear stress that these rivet materials can expose. And we need to use this biggest application of shear stress while selecting the materials and the sizes.
Also, corrosion resistance is a very important thing in rivet materials. For example, if we are using these fasteners in the applications such as sea, we need to have great corrosion resistance.
These are the general important features that we are expecting from the rivet materials in general.
Steel is one of the most common rivet materials in most applications. Because they possess very good hardness and ductility properties to prevent mechanical failures. Their shear strength properties are superior which makes them proper materials for rivet applications.
With the increasing carbon content, the total hardness value increases. But the ductility decreases. In the market, there are various kinds of steel rivets available for different applications.
Also, stainless steel is very important. The Chromium content makes the steel stainless. Stainless steel has very good corrosion and rusting resistance which is very proper for applications where the high exposal of corrosive media such as airplanes.
Copper and copper-based alloys are best for applications where corrosion resistance is the prime importance. Because copper has very good corrosion resistance. In submarine rivet applications, copper alloys are very common. Also, they have good mechanical strength.
The most important feature of the brass, they create sparks. In applications where inflammability and safety are important, the use of brass rivets is also very common. In gas containers, the use of brass material is very common.
Also with its shiny appearance, the use of brass rivets is very common in decorative applications.
Aluminum is a great material for lightweight applications where mechanical strength is not of prime importance. For example, external coatings for aircraft materials, and the use of aluminum rivets are so common. Also, they are very malleable making them very suitable for riveting applications.
As you see above, there are various kinds of materials and material groups for rivet applications. Also, if you consider the general types of these fasteners, you can realize that there are various kinds of rivets available.
Applications of Rivet Fasteners
You can understand that there are variıus kinds of and materials of rivet fasteners in the market. So, the use of rivets is very common in lots of kinds of applications. We gave several applications while we are giving real-world examples to state the general information. But there are more details about these applications.
Rivet fasteners are very common in household applications where the general fittings and assembly of the furniture. Because they provide a good appearance and decorative sight. For example, you can find them in the assembly of the furnishings and furnishings parts.
And also, they are very common in water fittings and household appliances such as refrigerators.
For appliances that you attach to the wall, you are probably using different dowels which are kinds of rivet applications.
Aircraft and Aerospace
In aircraft and aerospace applications, the use of rivet applications is very common. It is because they provide better permanent attachment of the body parts and they are very good for lightweight applications. The composite body parts of the planes are generally fastened with these types.
Also in marine applications, the use of this fastener is very common. Especially in aluminum hull applications, the use o rivets is so common. They provide very good structural integrity and permanent applications that are watertight. So, the unity of the hull depends on the rivet applications.
If you take a look at the trailers of the trucks, you will see that rivet applications are very common. Because they are highly resistant to loosening because they are permanent joints. Over thousands of miles, these fasteners save their mechanical integrity.
Leashes are very important structural parts to bind and fit different mechanical things. The applications of the rivets are also very common in leashes. So, their applications are very easy.
Window and Door Covers
As we stated above, the applications of these fasteners are very common in decorative applications. On window and door covering applications, you can find that rivets are very common. Also, at the coverings of the decorative objects, these fasteners do not harm the aesthetic unity of the parts.
As you see above, the use of rivet applications is very common in most places.
Advantages and Disadvantages of Rivet Applications
Like the other mechanical elements, there are advantages and disadvantages of these fastening applications that you need to consider before applying them. So, you will choose them wisely how to select one of them.
- The biggest advantage of these fastening applications, they are highly resistant to loosening of the attached parts. Because they are permanent joints that provide no disassembling like nuts and bolts.
- They provide very good structural support for the different kinds of applications. Because the use of the rivets is very tight and high in number in most of the applications.
- If we compare it with welding operations, this joining technique provides a much more decent joining of the surfaces. The mechanical strength can change along the welding site, but the spread of the load on rivet applications is more decent.
- Their applications of them are generally lower in cost if we compare with other permanent joining techniques. For welding, much higher work force and energy that we require if we compare with these operations.
- Also, we can state the permanent joint nature of these fasteners as a disadvantage. Because we can not disjoint the permanent joints in general. If we try to disjoint the rivet applications, probably we damage the parts and materials.
- In most applications, there are protrusions of the rivet head on the surface. This can be harmful to aerodynamic applications.
- Corrosion and rusting can be problematic issues. Because, once these fastening applications start to rust or corrode, changing them with new ones is not possible.
These are the general points on the riveting applications in general. Attaching and applications of these fasteners are very different than the other non-permanent fasteners. They are fasteners that have the possible sides of permanent fasteners and non-permanent fasteners. Because of this, their uses are very common in different places.
Furthermore, there are different kinds of rivet fasteners for different kinds of applications. Selecting the proper one can be a tough issue. But it will be helpful if you research which kinds of riveting applications are used in the application that you want to obtain. Also, minimal tricks about these applications above will be helpful to you.
Also, you can find the general applications above. As you see from marine to aerospace applications, the use of these fasteners is very wide. Also in household applications, rivets are very common.
Before applying to our applications, it is very important to know the general advantages and disadvantages of the riveting applications. This is because you will decide whether it will be a good or bad decision to choose them as the fastening.
Finally, do not forget to leave your comments and questions below about this topic.
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FAQs About Rivets
They are very important permanent fasteners in combining sheet metal as lap and butt joints. So, they are a very good alternative to welding operations for materials that are not weldable. The use of these fasteners is very common in marine and aircraft applications. And also, they are very common in household applications where we can not apply welding operations.
Yes, there are lots of kinds of applications that they use these fasteners. The general applications are aerospace and boat hull attachments, and sheet metal applications where welding is not possible. Furniture applications where a permanent joint is important. Also, we can multiply the samples that we use for the rivet applications.
They are the permanent fasteners that we use in different applications. The general types are; solid, blind, oscar, tubular, friction lock, flush, self-piercing, compression, and split rivets.
There can be different reasons for this problem. For example, if you are not using the correct ones to withstand loads of your application. If you use the thicker and bigger ones, it may solve your problem. Also, your attachment technique can be wrong. The use of riveting guns will also affect the structural integrity of your fastening. Checking your gun also will serve very well for you.
It depends on the applications. But if we take a look at the applications where we are using rivets, they perform better performance than the screws. This is because screws are the non-permanent joints where loosening will take place. But in these fasteners, we are not experiencing and loosening.