Calculate the length of blind rivets
Published 28/01/2025
Your comprehensive guide to calculating the length of a blind rivet
Blind rivets are an indispensable fastener for anyone who wants to create reliable and stable connections.
However, you often face the problem of choosing the right length of blind rivet. A blind rivet that is too short or too long can affect the strength and quality of the connection.
This article provides practical tips and simple examples to help you calculate the blind rivet length correctly. With these instructions and calculations, you will know exactly which blind rivet is the right one for your application.
Contents
Why is the correct length of the blind rivet important?
Calculating the correct length of blind rivets
Practical example of the calculation
Table for the correct length of blind rivets
What else is important besides the length of the blind rivet?
Common mistakes when selecting the right blind rivet
Conclusion
Frequently asked questions
Why is it important to use the right length of blind rivet?
Selecting the right length of blind rivet is crucial for the quality and strength of the riveted joints.
There is no standardised norm for the length of blind rivets as this is dependent on the manufacturer.
GESIPA uses the DIN 7337 norm, which covers the most common applications.
If a blind rivet is too short, it will not grip enough material and will not be able to properly secure the connection. This leads to unstable riveted joints and reduces the strength of the connection.
On the other hand, if a blind rivet is too long, it will leave too much material protruding, which can pose a risk of injury, affect the appearance and reduce the quality of the connection. The right length of blind rivet ensures a secure and durable connection.
Calculate the blind rivet length correctly
There is a proven formula for calculating the correct length of the blind rivets:
Rivet length: This is the total length of the blind rivets. They must be long enough to join the materials to be joined reliably and securely.
Grip Range: This describes the overall strength of the two parts being joined. Add the thickness of all parts to be riveted to get the overall strength.
Diameter: The diameter of the rivet affects the length required to secure the joint. A larger diameter requires a longer rivet to penetrate the material securely.
General rule of thumb
A simple rule of thumb is to use blind rivets that are at least
1.5 times as long as the grip range.
This rule ensures that sufficient material is gripped to
create a strong joint.
Practical example of the calculation
A simple example clarifies the calculation of the correct
blind rivet length:
• You want to connect two sheets with a blind rivet.
Both sheets have a thickness of 3 mm each.
• The bore has a diameter of 4 mm.
According to the above formula, this results in:
• Grip range: 3 mm + 3 mm = 6 mm
• Diameter: 4 mm
The appropriate blind rivet has a length of:
• Rivet length = 6 mm (grip range) + 4 mm (diameter) = 10 mm
In this case, a blind rivet of size 4 x 10 mm would be ideal.
It ensures a strong joint by gripping enough material
and providing the right clamping length.
Table for calculating the correct blind rivet length
The following table will help you to find the right GESIPA® blind rivet length for different grip ranges and diameters.
Multigrip blind rivets: A GESIPA® PolyGrip® blind rivet can replace up to five different sizes
of standardised blind rivets. This means that the grip range is significantly larger and allows a wide range of applications
with just one size.
Standard blind rivets
PolyGrip® multigrip blind rivets
This table provides a quick overview for common applications and shows which blind rivets are recommended for different joints.
These values apply to GESIPA® blind rivets. These values may differ for blind rivets from other manufacturers.
What is important besides the length of the blind rivets?
In addition to the correct length of blind rivets, there are other aspects that are crucial for the quality of the riveted joints:
TYPE OF MATERIAL
The type of material you are joining plays an important role.
Metal tolerates sturdier rivets, while plastic requires blind rivets that do not damage the brittle/delicate material during the setting process.
DIAMETER MATCHED TO THE HOLE
The diameter of the blind rivets should always match the hole. Make sure that the hole is about 0.1 mm larger than the diameter of the
rivet so that it can be easily set and is securely anchored in the material.
USING BLIND RIVETS WITH SPECIAL CHARACTERISTICS
For certain applications, you need special blind rivets, such as waterproof rivets or rivet nuts.
These offer additional functions and increase the durability of the connection.
Common mistakes when selecting the right blind rivets
There are some typical mistakes that can be made when choosing the right blind rivets:
Rivet body too short or too long
A blind rivet that is too short does not grasp the entire material to be joined, which impairs the stability of the connection. A rivet body that is too long will stick out unattractively and can also weaken the strength of the connection and cause injuries.
Incorrect handling of the hand rivet tool
Incorrect use of the hand rivet tool can affect the quality of the connection. Make sure that you guide the mandrel correctly and apply the necessary force to set the blind rivets securely.
Incorrect choice of diameter
If the diameter is too small or too large, the rivet will not be properly deformed and the connection will remain unstable – or it may not fit into the drill hole at all.
Conclusion
Calculating the correct length of blind rivet is an important step in ensuring that your joints are as strong as they can be. With the simple formula of grip range and diameter, and the handy table, you have the best tools at hand to quickly and easily select the right blind rivet.
The example shows how to determine the length precisely and the advantages of the correct grip length. GESIPA, as a specialist in the field of blind rivets, provides you with high-quality rivets that guarantee a reliable connection.
Avoid typical mistakes and use the tips described here for your future projects. A correctly calculated blind rivet results in a more stable and durable connection. Try it out and see how easy it is to find and use the right blind rivet.
FAQ
What is the grip range of blind rivets?
The grip range of blind rivets describes the thickness of the material that you want to join with the rivet. It indicates the maximum thickness of the workpieces for the rivet to hold properly.
Make sure you choose the right grip range. If it is too small, the closing force will not be sufficient. If it is too large, the rivet may not close properly and could wobble. You should always use the grip range that is right for your application to ensure a secure connection.
How big should the drill hole be for blind rivets?
When drilling for blind rivets, select a drill bit diameter that matches the size of the rivet. The drill bit diameter should be slightly larger than the rivet body. This ensures that the rivet fits easily and can be set securely.
Use the manufacturer's specifications as a guide. Typically, you would drill a hole with a diameter of 4.1 to 4.2 mm for a 4-mm rivet. Make sure to drill the hole precisely to ensure a stable connection.
How can you tell if you are using the right nosepiece?
You can recognise the right nosepiece by the fact that it matches the diameter of the rivet exactly. The rivet should fit into the nosepiece without play and be held securely.
Make sure that the nosepiece grips the rivet firmly during the setting process and deforms it correctly. If the rivet is not seated properly or the nosepiece is too large or too small, the connection will not be stable. Therefore, always use the nosepiece that matches the rivet size.
