WHAT ARE BLIND RIVETS AND HOW ARE THEY MADE?
- RIVET BODY
- MANDREL HEAD
- BREAKING POINT
- RIVET BODY SHANK
- MANDREL RETENTION
- RIVET BODY HEAD
- MANDREL TIP
What is a blind rivet?
A blind rivet is a mechanical fastening system that acts as a junction between two surfaces. It is used whenever it is not possible to make welds, like for example between two metal sheets. It is the ideal solution when applications are accessible only from one side.
How is a blind rivet made and how does it work?
A blind rivet is formed by two components: the rivet body (that is the rivet “head”) and the mandrel (the longest part that protrudes from the body).
By a riveting tool, the rivet body is inserted into the hole on the two sheets, and the mandrel is pulled until the body is deformed so that it joins together the two surfaces. At the same time, a breaking force is applied to the mandrel, which is then torn off and removed from the application.
Once installed, the rivet can no longer be disconnected.
DIFFERENT TYPES OF BLIND RIVETS
There are several types of blind rivets, and it is important to know the details of the application on which they are to be installed in order to choose the right one.
Here are some examples:
- Hole diameter: knowing it enables to choose the right diameter for the rivet body
- Grip: knowing the thickness of the material that the rivet has to fasten, allows to determine the length of the rivet body
- Materials to be fastened: depending on the type of materials to be fastened, it might be better to choose a specific metal alloy rather than another, or for example a non-standard head.
- Shear and tensile resistance: with non-standard applications, it may be essential to know which stresses the rivet is subjected to once installed, and the characteristics of mechanical resistance required.
SARIV blind rivets can be divided in 3 macro-categories: standard, special, and structural.
These rivets require no particular mechanical resistance, but they are still simple, fast and economic solutions that guarantee an excellent fastening quality.
The material combinations of body and mandrel can be various, choosing among Aluminum, Steel, Stainless Steel, Copper and Copper nickel.
Another variant is the type of rivet body:
- Dome head blind rivets: it is the standard rivet head, suitable for any type of application.
- Countersunk head blind rivets: ideal for applications with a countersunk hole; once applied, the rivet head is flush with the sheet, without protrusions.
- Large or extra-large head blind rivets: a larger head increases the bearing surface, which prevents breakage in the sheets in the case of fragile materials.
Compared to standard blind rivets, special ones have improved features to be more performing on certain materials (eg wood, plastic, etc.) and applications (such as closed holes, extra-large holes, etc.).
SARIV special fastening systems are:
- Multigrip blind rivet: this rivet covers different thicknesses with the same length, moreover the mandrel head remains in the body after installation.
- Peel blind rivet: its name is due to the way it opens while installing, in fact it opens up in several parts to ensure fixing also on uneven surfaces; it is ideal for use with soft materials.
- Sealed blind rivet: being closed, it guarantees protection from water infiltration; the head of the mandrel that remains anchored to the bush increases its resistance to vibration.
- Three wings rivet: this aluminum rivet is the evolution of the peel rivet, ideal for soft materials and for oversized holes.
- RAL rivet: rivet with body died in epoxy paint, ideal for pre-painted surfaces such as curtain walls; we stock three standard colors, but we can supply any RAL upon request, and die also the entire rivet.
- Electrical blind rivet: thanks to its copper body, copper-plated mandrel, and brass faston, it can be used as a connection inside electrical panels.
- Grooved blind rivet: its body is undulated, which favors greater anchoring to the sides of the hole.
In addition to the products in our catalogue, we also offer a free consulting service to design and produce customized solutions based on the needs of our customers.
A distinctive feature of structural blind rivets is that, in addition to the body, also the mandrel plays an active role inside the application to achieve the required mechanical characteristics. In particular, after the installation the mandrel is locked inside the rivet body, allowing to reach the highest mechanical values among blind rivets.
We produce 5 families of structural rivets:
- Saribulb: this rivet has high shear and vibration resistance, and excellent filling of the hole for a good hermetic sealing. Thanks to these features, it can be used even for asymmetric and / or slotted holes.
- Saribolt: high shear and tensile resistance, and excellent vibration resistance. Since the hole is completely filled in once applied, it also ensures hermetic sealing to liquids. The application requires a special nosepiece.
- Saribolt Plus: this is the version of Saribolt modified so that the rivet can also be applied with a standard nosepiece.
- Sarilock: in addition to very high mechanical strength given by its double-diameter mandrel, this blind rivet has a very high clamping force, so it is possible to fasten together very thick sheets.
- Sarilock Plus: this rivet is the improved version of Sarilock, thanks to the use of a higher carbon content steel.
How do you apply blind rivets or blind rivet nuts? With specific riveting tools.
We have a wide range of products: depending on the size of the rivet to be installed, the frequency of installation, the type of application and in general all the various requirements, you can chose a manual or oil-pneumatic riveting machine, or a standard or long levers one.
Here is the range of tools offered by SARIV:
- SAR001: for blind rivet nuts between M3 and M12
- SAR002: for blind rivets with diameter between 2,4 and 4,8/5 mm
- SAR008: for blind rivets, for blind rivets having diameter between 3,0 and 7,8 mm
- SAR003: long levers, for blind rivets with diameter between 3,0 and 7,8 mm
- SAR004: long levers, for blind rivet nuts between M4 and M10
- SAR006: for blind rivets with diameter between 2,4 and 4,8/5 mm
- SAR007: extensible, for blind rivets with diameter between 3,0 and 7,8 mm
BLIND RIVETS APPLICATIONS: MATERIALS AND SECTORS
Thanks to the wide range of possible choices, the blind rivet is a fixing system that can be used in several industries.
Here are some examples:
- Automotive Industry
Automotive industry makes extensive use of fastening systems, in particular structural rivets are those that are used the most thanks to their high mechanical performance, especially shear, tensile and vibration resistance.
Some examples? Surely you will find rivets in the exhaust systems of your cars, in the chassis, in the doors to keep the speakers anchored, in the steering column, in the luggage rack, in the seat structure, and much more.
Having as its main focus both the safety of drivers and the performance of vehicles, it is a very selective sector with extremely high-quality standards. To guarantee the best possible response to these requirements, from May 2018 we obtained the IATF Certification 16949: 2016, the international standard of quality management systems in the automotive industry.
- Shipbuilding Industry
For the construction of ships and accessories for the marine sector, the most requested rivets are those with greater resistance to erosion and water.
Among our catalog products, we offer A4 stainless steel or copper nickel rivets. But we can develop special versions with specific surface treatments, which better withstand exposure to the saline environment.
In the field of constructions, the blind rivet is a suitable fixing system for the production of structures such as scaffolding and shelving.
In this case it is very important that the rivet has a high mechanical strength especially when cutting, in fact Sarilock is the system mostly used for this kind of application.
- Medical Applications
On a medical level, rivets are used in the construction of hospital equipment and machinery, prams and child seats, chemical toilets and mobile devices on wheels.
In this case, stainless steel, three wings or extra-large head rivets are the most suitable ones.
- Household Appliances
Washing machines, dishwashers, ovens, air conditioning systems. Here are some examples of the application of our rivets on household appliances.
Our mass rivets are ideal in this sector because they are at the same time a fixing system and also an electrical connection. Stainless steel rivets instead are ideal in ventilation systems for they resist corrosion.
- Construction Industry
In the construction sector, blind rivets have several different uses, and in this case not only the technical factor but also the aesthetic one matters: RAL rivets are in fact the most used system for curtain walls, and the possibility of producing a RAL on sample allows to chromatically harmonize the rivets with the materials used by the manufacturers; copper rivets are the most indicated for gutters; in windows instead the resistance to corrosion comes into play, and it is guaranteed by rivets in stainless steel or with customized surface treatments.
- Industrial assets and machinery
Rivets that resist corrosion and vibrations are widely used in systems such as elevators, tanks, large air conditioning systems, heat pumps, electrical cabinets and photovoltaic systems.
PRODUCTION AND QUALITY
The key word around which SARIV production revolves is traceability.
Having every single production step under control is fundamental for us, which is why we have chosen to carry out internally as many processes as possible, including thermal and washing treatments.
Developing Industry 4.0 philosophy, every step of Sariv production chain is digitally monitored through an MES (Manufacturing Execution System), in order to record the complete story of each single lot.
Before the production process, the monitoring starts from the raw material: all the wire we receive must be traceable from the point of view of heat, chemical composition and mechanical characteristics.
Each stage of the production process then, including product tests, is followed and recorded digitally on a database.
This ensures that we achieve the quality standards that our customers require, but that we primarily set ourselves as a goal.
A further aspect we care about is trying to minimize our environmental impact.
For a long time we have carried out some green initiatives that are constantly evolving: we aim at a constant reduction of waste; we use energy from photovoltaic sources to power our activities; we use an innovative washing system with modified alcohol that has allowed us to eliminate the use of water in degreasing processes; we have enriched the production with plants that act as a sentinel for the healthiness of our workplace.
What sets us apart in the fastening systems market is the ability to develop customized solutions for our customers.
The fact of producing the rivets internally, from design to packaging, opens up a range of infinite possibilities.
Here are some examples:
- Packaging: the packages can be branded with the customer’s logo, or we can supply products in neutral boxes, with specific quantities per box different from the standard if requested.
- Labeling: the labels on the packages can be modified by entering specific data requested by the customer, including for example logo, production batch, cross reference and so on.
- Product engineering: a dedicated consulting office is in charge of developing custom rivets with ad hoc features, defined starting from the customer’s application. Indeed, it is possible that the standard rivets are not performing in particular cases and there the need for an “evolved” version with tailor made technical features. For example, we can create blind rivets with a long nail, a head of a particular size, dedicated surface treatments, or specific mechanical characteristics.
- Sorting: we also have a sorting department via cameras that allows us to supply products with a sorting rate up to PPM 50. With this technology, we can carry out both dimensional and qualitative checks, with a speed of up to 350 pieces per minute.
- Certificates: for all our products we can supply specific documentation such as 3.1 certificates, dimensional reports, traction reports, salt spray resistance tests, and PPAPs required by the Automotive industry.