What is a rivet? Understanding rivets and the different blind rivet types.

Rivets are ever so popular because they are a quick and easy fastener to join two or more pieces of material. A strong reliable option that provides a secure solution via a power rivet gun or a manual rivet-tool. In this blog we aim to provide a comprehensive beginners guide to rivets. Essentially a rivet is composed of two components, a metal tube (body) & pin (mandrel). The pin is normally longer than the tube and designed to be pulled up through the tube whilst enlarging it in the process. As the body expands and buckles it secures the material between the two ends. At a predetermined point, the pin used to pull up the body will break, and drop off. See the image below for the anatomy of a typical rivet.

There are numerous rivet types for virtually any application; from connecting your home’s guttering with general purpose open-end rivets through to the cars we drive and the planes we fly with Huck rivets. Rivets are available in a range of different metals including steel, stainless-steel (grade 304 & 316) etc. with some options in a combo of different materials like the popular steel & aluminium. This article is an in-depth guide to rivets and you will find Aerobolt® is the leading supplier of rivets with the know-how to assist with all things rivets including rivet type, size and application; plus rivet gun selection with Riley the rivet lad. 

What are the key advantages of rivets?

Key benefit of a blind rivet is simple; they are fast & easy low-cost fastener. Rivets work well for the joining of many different types of material, including sheet metals, composites and so much more. Unlike welding, a rivet is ideal for the joining of different type of materials.

• One side assembly means quick installations, as access to the rear is not required
• Highly resilient, forming a mechanically activated permanent joining solution.
• Easy to use air, cordless, and manual rivet-tools that requires minimal effort and training.
• Design flexibility, wide range of rivet types and materials to suit most applications.
• Easy inspection and maintenance, no expensive equipment for quality control.

What are the main rivet types?

Listed here are the different types of blind rivet sub-categories plus some specialised industrial strength structural rivets. There are many other different types of rivets including semi-tubular, split rivets, and solid rivets however in this blog we are reviewing blind rivets. Blind pop rivets are the most common type of rivets.

Selection criteria should be based on the application connection you believe is required, whether your job involves installing lightweight guttering & fascias through to heavy duty truck fabrication. There are numerous rivet terms for the same rivet type and in this blog we have incorporated the different descriptions into the rivet type heading.   

Rivet. General purpose rivet types.

Open End Rivet. (Rivet, Pop Rivet or Blind Rivet).

Open end rivets means the rivet body is hollow i.e. "open end tube" (body). This is the most common rivet type and the least expensive. Available in a range of materials, including a steel & aluminium combo, all-steel, all-aluminium, stainless- steel & steel, or all-stainless steel (both grades 304 & 316). This rivet is ideally suited for metal trim applications and other lightweight installations. Open end rivets also has the widest range of different head style types covering dome head, truss head, or large flange and countersunk head.   

Closed End Rivets. (Sealed Rivet).

Closed end rivets have a cup shaped end configuration that eliminates water ingress from within the body of the rivet, but not between the outside of the body and the material. Many customers purchase sealed rivets believing they are 100% waterproof, unfortunately this perception is not entirely correct without a rubber washer. A closed-end rivet compared to an open-end rivet of the same size & material, provides better shear and tensile strength.

Multi-Grip Rivet.

Multi-Grip rivets are a strong & highly flexible option due to their extended material grip range. The multi-grip is the strongest standard rivet choice, for many this rivet helps reduce stock options as one multi-grip rivet replaces a few different size open end rivets. Which in turn assists to reduce cost and minimise operator error. A multi-grip rivet, compared to an open-end rivet of the same size & material, provide greater shear and tensile strength. Check the blog Multi Grip Rivet V's Open End Rivet.  

Tri-Fold Rivet.

Aluminum tri fold rivet is a split or slot body rivet that is designed for the assembly of lightweight materials such as fibreglass, plastics, & composite material. This rivet forms a propeller shape anchor on the blind side of the material without damaging it. Tri-folding rivets or sometimes known as load spreading rivets are installed with the same type of rivet gun that install all other standard type rivets. Read more about Tri-Fold rivet V's Bulb-Tite Rivet. 

Peel Rivet.

Peeled rivets are ideal for the joining of softer material such as timber, plastic, rubber, fibreglass, and laminates. Upon installation, the rivet body splits into petals that bends outwards, like peeling a banana. The petals bend out and contact the blind side of the material, creating a large anchor head.

Grooved Rivet.

Groove Rivets are designed to be installed within a hole as they infuse themselves into the material, making it ideal for soft materials such as timber, plastics & other fibrous material. When set correctly, the annular rings around the body will expand and embed themselves into the surrounding material. This means the rivet does not require an open end hole to work as it sets itself within the material.

Structural Rivet. Industrial strength rivets.

Huck Rivet Magna-Lok. (Monobolt®).

Huck Rivet - Magna-Lok® is a versatile structural rivet that is ideal for multiple material grip ranges. This rivet has Huck’s unique internal locking mechanism that provides a high resistance to vibration & moisture. Fast and easy to install using conventional Huck gun or a structural rivet gun. Aerobolt is Australia's number #1 Huck distributor with the complete range of structural rivets and structural rivet tools. 

Allok Rivet. (High Strength Rivets, Orlock Rivets).

Allok®, High Strength Rivets, and other blind side bulb forming rivets like Orlock rivets feature a double-locking system that secures the material on both sides of the panel for great strength, providing a vibration and weather resistant joint. It's non-protruding blind side bulb spreads the load, whilst avoiding pull-through. Easy to install via a Huck gun & other structural rivet-tools as a standard rivet gun is not engineered to install structural rivets. This rivet type is also known as Orlock® rivet, Hemlok® rivet or Ornit® rivet. 

Bulb-Tite Rivet (Huck-Tite, Tri-Bulb).

These rivet differs from other types due to their slotted bodies that create a propeller shape blind–side anchor which combines with a washer to provide a weatherproof joint. Bulb-Tite®, Huck-Tite, and many other tri-folding split body rivet with washer spreads their clamping force through the anchor blades whilst providing excellent pull through resistance, making them an ideal choice for lightweight panel applications, humid conditions, or where water might be an issue. Read about Bulb-Tite Rivet V Tri-Fold Rivet.

Self-piercing rivets.

This is another category of rivet, a self-pierce rivet joins two or more layers of material by piercing the top layer of material and then flaring out at the bottom layer, forming a mechanical interlock. As the name suggests predrill holes are not required, allowing for a rapid, strong, fastening solution that would suit numerous applications. This item is not on our site, however we do stock them so feel free to phone on 02 9755 3747 or contact us.   

How do I select the right rivet?

Selecting the right rivet type, diameter and length depends entirely on the application and the material you are riveting. Here we will review the factors that will assist in selecting the correct rivet for your situation. 

Rivet Material.

Rivet material type provide a good guide to their strength. As a general rule; an aluminium body with aluminium pin is not a very strong rivet; aluminium body with steel pin are a little stronger; steel body with steel pin are strong rivets; and stainless-steel body with either steel or stainless-steel pin make for a very strong rivet. Use steel rivets for heavy duty applications and aluminium rivets for lightweight jobs. 

Ensure the rivet material is compatible with the material being joined to minimise galvanic corrosion. This is a process which occurs when dissimilar metals are in contact with each other. Avoid using aluminium and stainless steel together, we recommend keeping the metal material like for like. Stainless with stainless, aluminium with aluminium, etc. When reviewing material, you will need to consider environmental factors, such as temperatures and or salt sprays etc. See the table below as a general guide.

Rivet Diameter and Hole Size.

Rivet diameter selection is guided by the material gauge, for instance use small diameter rivets for lightweight application and larger diameter rivets in heavy duty fabrication. The larger the diameter the stronger the rivet, as a general rule the rivet diameter should be about three times the thickness of the thickest piece of joined material.

Drill hole size is also important. If the rivets diameter is too small for it's hole you will not be able to insert the rivet body into the material or if the hole is too big it will fail to clamp the material. Referring to the hole diameters before drilling is an easy way to avoid issues later, see the table below covering diameters and corresponding hole sizes.

Rivet's Material Grip Range.

The material grip range refers to the material thickness or the depth the rivet can be effectively installed. For example, if two 1.5 mm plates/items need to be riveted, a blind rivet with a material grip range between 2- 5 mm is required. Best practice dictates that you should aim for the middle grip range of a rivet, followed by the minimum grip then the maximum. This assists in achieving correct shear and tensile strength whilst ensuring the longevity of the rivet. Please note that the grip range is not the length of the rivet as many people mistakenly believe the length is the amount of material the rivet will pull up.

WARNING; If you are below the minimum grip range the rivet will be loose and if you are over the maximum, the rivet may not set correctly. Either way the joint will be compromised. 

Listed below we have a table listing standard blind rivet material grip ranges and their corresponding grip code.  

Rivet Head Type.

Rivet head assists in holding the material together and enhances its appearances. Dome head is shaped like a small portion of a ball that sits proudly above the material, whilst the large flange or truss head is a shallower broader profile. The large flange or truss head has double the bearing area of the dome head which makes it ideal when fastening rubber, plastics or fibreglass as the head has greater coverage. The countersunk option provides a flush neat finish subject to countersinking a hole first, allowing for the head to sit level with the surrounding material.  The countersunk rivet is also known as a flush head rivet. The image below covers the typical head types plus a few specialised rivet type profiles.

Pop rivet Vs blind rivet. 

This is a common customer clarification. The answer is there is little difference between Pop® rivet, pop rivet, and blind rivet. These are different terms for the same item, a blind rivet means you do not need access to the other side of the working piece, or you can't see the other side of the material. Also known as pop rivets because this is the name of the original rivet company-Pop®, also this is the sound rivets make upon installation.   

Frequently Asked Rivet Questions.

How do I order rivets?

There are number of different type of rivet code formats. At Aerobolt we use the same product code system as "Marson® Rivets" which is a division of Howmet Aerospace.  Rivet code prefix begins with the "body material", followed by the "head type" both of these are letters. Then "body diameter" dash & then "grip range", both of which are representative numbers, rather than actual measurements. The code concludes with another letter for the pin material. 

In the above product code example (in the red box), beginning from left to right we have:

A = Aluminium body material. Other options include (S = Steel, SS = Stainless, etc.).
B = Button / Dome Head. Or you can select (T/LF = Truss/Large Flange, C = Countersunk) 
6 = 4.8mm (3/16") body diameter. Other options are; 4 = 3.2mm (1/8"), 5 = 4.0mm (5/32"), 8 = 6.4mm (1/4").
6 = 7.9 - 9.5mm this is the material grip range. See grip codes number table in previous section. 
S = Steel pin/mandrel material. The other options are (SS = Stainless, A = Aluminium etc.).

How do I remove a rivet?

Rivet removal is straight forward with the right tools. This requires the destruction of the rivet, and the best method is to drill it. You will need, a drill, drill bit, long nose pliers, & safety accessories such as glasses and gloves.

Steps: Use your safety glass & gloves before starting the drilling process. Place the drill bit against the rivets’ center pin and drill through the body at a low but steady speed. Once drilling is completed, pull the rivet off with your long nose pliers. How easy was that!  

How do I install a rivet?

To install a rivet is simple with practice, pre drilling of holes is required. Load rivet’s pin tail section into rivet gun. Insert rivets body into hole and activate gun. Upon activation the head of the rivet is pushed against the outer surface of the tool, whilst the tool pulls up the central pin. As a result, the bottom portion of the rivet compresses, and expands on the blind side. This expansion increases until it reaches approximately one and a half times the size of the original diameter. Resulting in a larger surface in which the two materials are effectively fastened together.

How does a rivet work?

How rivets work is ingenious. Essentially a rivet is composed of two components, a metal tube (body) & pin (mandrel). The pin is normally longer than the tube and designed to be pulled up through the tube whilst enlarging it in the process. This results in the expanded tube clamping the material between the two ends of the tube. See the image below to better understand how a rivet works.

Which is the best rivet gun?

Selecting the correct rivet gun depends on several factors that relate to your specific requirements, rivet gun section is covered in the blog; Ultimate Guide to Rivet Guns.

Which is the strongest rivet? 

We have taken the guess work out of rivet selection with our lab test results table below. Structural blind rivets are the strongest option on the market due to the unique combination of internal pin retention & locking mechanism that creates their inner strength. Aerobolt has the complete Huck Structural Rivet range including the original multi-grip rivet "Magna-Lok", the Huck Rivet "Magna-Bulb" with its superior installation values and the hybrid of the two "Hucklok Rivet". The strongest structural rivet option is  Huck Rivet "Magna-Bulb" refer to the table below to compare a range of structural rivet results.

Can I get coloured rivets?

Yes, painted rivets are available. They cost a little extra compared to the mill (raw) finish and are available in a wide range of colours. Refer to the Colorbond ® colour chart for your selection of colours. Most fastener painting operators will not consider colours outside of the colorbond® range.  

Why have my rivets failed?

There are several reasons your rivets may have failed, the issue could be a dodgy rivet from a shifty supplier or an installation issue. Either way we offer a wide range of technical services, including rivet testing lab services. We have teamed up with a NATA approved lab that undertakes laboratory rivet testing services. Should you have a rivet failure, let us know  the rivet label, size, and  material depth so we can review your application and or have your rivets sent to the NATA approved lab for laboratory rivet testing.   

When is it better to use a rivet rather than a bolt and nut?

Bolts & nuts offer a useful combination of strength & convenience, and are an ideal solution in static applications i.e. where movement is at a minimum. The disadvantage of these fasteners is their poor resistance to vibration, this means over time they lose their grip. Huck bolts and Huck's structural rivets have overcome the issue of loosening, so in this instance the right answer is in the application.  

Who invented the blind rivet?

In 1934 the George Tucker Eyelet Company was approached by an aircraft manufacturer to develop a fastener that could be set from just one side of the material. This lead to the world famous POP® rivet—named for the “popping” sound it makes during installation. They are now owned by Stanley Engineered Fastening, a division of Stanley Black & Decker.

What's the difference between a pop rivet & blind rivet? 

This is a popular question that many people ask. The short answer is there is no difference between Pop® rivets, pop rivets, or blind rivets. These are different rivetlabels for the same item, a blind rivet means you do not need access to the other side of the material, or you can't see the other side of the material. Also known as pop rivets because this is the name of the original rivet company-Pop® and this is the sound rivets make when installed.   

What are Drive Rivets? 

Drive rivets are an easy to use rivet where you insert into a hole & drive pin flush to the top of the rivet head with a hammer or air tool. Pin forces prongs to flare out and lock the material. 

Why are rivets used on aeroplanes?

Rivets are preferred for the construction of aeroplanes because they can withstand extreme stress. They are renowned to withstand extreme stress without breaking and hardly succumb to damage. Rivets are used in aerospace manufacturing because it simplifies both production and maintenance.  

Which is the strongest general purpose rivet? 

Stainless steel rivets are the strongest standard blind rivet. They have an excellent ability to resist corrosion, and are considerably harder and stronger than other material types. They can withstand extreme temperatures and maintain their strength even after long periods of time.

While stainless steel ones are stronger than aluminium rivets, they're also more expensive. 

Can you assist with rivet selection?

Sure we can help with rivet selection and so much more. We are one of Sydney's leading rivet supplier with a comprehensive range of general standard rivets plus industrial strength structural rivets including rivet guns. You can reach us by either telephoning 02 9755 3747 or via the contact us page.  

Do you deliver rivets throughout Australia?

Yes, we can deliver Australia wide through our network team of courier companies. In Sydney we offer our customers same day delivery if you order before 10.00am or the next day. Deliveries to regional New South Wales or major Australian cities such as Melbourne, Brisbane including regional South Eastern Australia are either next day delivery or 2 days turnaround.

Ultimate Guide to Rivets Summary.

Rivets offer superior fastening capabilities for both heavy-duty and light fabrication applications. They are found in the metal roofing and guttering that protect our homes, to the air conditioners that make us more comfortable to the cars we drive, the planes we fly and the ships we sail. Wherever there is a construction site or a fabrication workshop there is bound to be a rivet in use. 

At the conclusion of this blog, it is evident that rivets are important option in numerous building and manufacturing sectors. Irrespective of the rivet type its clear with a little rivet insight your next rivet project can be a successful one. Here at Aerobolt we have a comprehensive range of rivet products and can assist in your application, simply call us on 02 9755 3747 or contact us for all your Australian riveting supply requirements. When considering rivets, think Riley the rivet lad.  

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