Ultimate Guide to Blind Rivets

Huck Aerobolt - The Ultimate Guide to Blind Rivets

What is a rivet?

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 rivet gun. 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 it secures the material between the pin head & the setting head. 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 standard rivets through to the cars we drive and the planes we fly with structural rivets. Rivets are available in a wide range of metals including steel, stainless (304 & 316 grade) & aluminium plus in a combo of different materials like steel & aluminium.It's almost impossible to imagine today's world without rivets and this blog is a starters guide to rivets. Aerobolt we can assist with both the numerous rivet options, and their application, including rivet gun selection.  

Typical Standard/Pop Rivet

 

What are the advantages of rivets?

The key advantage of a rivet is; they are a fast & easy to use, low-cost fastener. Rivets work well for joining of many different types of material, including thin sheet metals, composites and so much more. 

  • 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 require minimal effort and training.
  • Design flexibility, wide range of types and materials to suit most applications.
  • Easy inspection and maintenance, no expensive equipment for quality control.

    What are the main rivet types?

    Here we list the common types of blind rivet sub-categories plus some specialised industrial strength structural rivets. Your selection criteria should be based on the application connection you believe is required, whether your job involves installing lightweight guttering & fascias or heavy duty truck fabrication. There are numerous rivet labels for the same rivet type and in this blog we have incorporated the different descriptions into the title.   

    Rivets. Standard blind rivet types.

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

    Open end rivets means the rivet body is hollow i.e. "open end tube (body)". This is the most common rivet avaliable and the least expensive. Available in a range of materials, including steel & aluminum, all steel, all aluminum, stainless & steel, all stainless, nickel & copper. This rivet also has the widest range of different head syles; dome head, truss or large flange and countersunk.  

    Closed End Rivets. (Sealed Rivets).

    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. A closed-end rivet compared to an open-end rivet of the same size & material, provides better shear and tensile strength.

    Multi-Grip Rivets.

    Multi-Grip rivets are a strong & highly flexible option due to their extended material grip range. The multi-grip is our 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. This assists to reduce cost and minimise operator errors. A multi-grip rivet, compared to an open-end rivet of the same size & material, provide greater shear and tensile strength.

    Tri-Fold Rivet.

    Aluminum tri-fold rivets are split or slot body rivets that are designed for the assembly of lightweight materials such as fibreglass, plastics, thin steel sheeting & composite material. This rivet forms a propeller shape anchor connection on the blind side of the material without damaging it. Tri-folding rivets are installed with the same type of rivet gun that install all other standard type rivets.

    Peel Rivets.

    Peel rivets are also 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.

    Groove Rivets.

    Groove Rivets are designed to be installed within a hole as they infuse themselves into the material, making them ideal for soft materials such as timber, plastics & other fibrous material. When set correctly, the annular rings around the body will expand into the surrounding material.

    Structural Rivets. Industrial strength rivets.

    Huck Rivet Magna-Lok. (Monobolt®).

    Huck 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 brand 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 Rivets. (High Strength Rivets, Orlock Rivets).

    Allok®, High Strength Rivets, and other bulb forming 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 has a non-protruding blind side bulb that 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 built to install structural rivets. This type is also known as Orlock® rivet, Hemlok® rivet or Ornit® rivet. 

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

    These rivet differs from other types due to their slot body that creates a propeller shape blind–side anchor that combines with a washer to provide a weatherproof joint. Bulb-Tite®, Huck-Tite, and many other tri-folding split body rivet 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. 

    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.   

    Self-Piercing Rivet

    How do I select the right rivet?

    Rivet selection is easy, you will need to consider rivet material, rivet diameter size, and thickness of the material you are riveting.  

    Rivet Material.

    The rivet is categorised by the material of the body and then the material of the pin. For example, you might see “aluminum/steel”, which means an aluminum body with a steel pin. These fasteners typically come in steel, stainless steel, or aluminum or in a combination of these materials.

    Rivet material type provide a good guide to their strength. As a general rule; an aluminium body with aluminium pin is not very strong; aluminium body with steel pin are a a little stronger; steel body with steel pin are stronger still; and stainless-steel body with either steel or stainless-steel pin are the strongest. 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 avoid galvanic corrosion. Avoid using aluminium and stainless steel together, we recommend keeping the metal material like for like for maximum life. Stainless with stainless, aluminium with aluminium, etc. When reviewing material, you will also need to consider environmental factors, such as extreme temperatures or salt sprays. See the table below as a general guide.

    Rivet Material Compatibility

    Rivet Diameter & Hole Size.

    Rivet diameter selection is guided by the material gauge, for instance use small diameter rivets with lightweight fascia covers and larger diameter rivets in the fabrication of checker plate tool boxes. The larger the diameter the stronger the rivet. Drill hole size is also important. If the rivets diameter is too small for its hole the fastener will fail. Referring to the hole diameters before drilling is an easy way to avoid issues later.

    Refer to the table below covering diameters and corresponding hole sizes.

    Diameter Codes & Grip Ranges

    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 the middle grip range of a rivet should be used and not the minimum/maximum sizes. 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 Grip Codes & Ranges

    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, which sits proudly above the material, whilst the large flange or truss head is a shallower broader profile & well suited for thin or soft material items like rubber or fibreglass. 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 image below covers the typical head types plus a few specialised rivet type profiles.

    Rivet Types

    Pop rivet Vs blind rivet. 

    This is a popular customer clarification. The answer is there is no difference between Pop® rivet, pop rivet, and blind rivet. These are different labels 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.   

    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 as "Marson® Rivets" which is a division of Howmet Aerospace.  Rivet code begins with the "body material", followed by the "head type","body diameter" dash & then "grip range" (both of which are representive numbers, rather than actual measurements). The code concludes with the pin material. 

    Rivet Code Identification System

    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 rivets?

    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.

    How Rivets Work

     

    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 blind rivet? 

    Structural rivets are the strongest blind 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's lab results.

    STRUCTURAL RIVET TYPE KEY LAB METRICS FOR STEEL 6.4MM (1/4")
    Shear Typ. (kN) Tensile Typ. (kN) Grip Range (mm)
    Magna-Lok® (HRDS-0806) 11.1 8.2 2.0 – 9.5
    Hucklok® (HKLP-R8-6) 15.6 8.5 2.0 – 9.5
    Magna-Bulb® (MBDS-0806) 16.0 8.9 5.8 – 7.8
    Allok® (ARDS-08145) 13.7 7.9 5.0 – 8.5

    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. 

    Why have my rivets failed?

    There are several reasons your rivets may have failed, the issue could be a dodgy rivet or an installation issue. Either way we offer a wide range of technical services, including rivet test 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 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 minmum. The disadvantage of these fasteners is their poor resistance to vibration, this means over time they loosen and 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 Co. 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—which is now owned by Stanley Engineered Fastening, a division of Stanley Black & Decker.

    Whats the difference between a pop rivet & blind rivet? 

    This is a popular question that many customers ask. The short answer is there is no difference between Pop® rivets, pop rivets, and blind rivets. These are different labels 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.   

    Why are rivets used on airplanes?

    Rivets are preferred for the construction of airplanes because they can withstand extreme stress. They are said to withstand extreme stress without breaking and they hardly succumb to damage. They are used in aerospace manufacturing because it simplifies both production and maintenance.  Another reason why rivets are used because aluminium materials used are intolerable to heat.

    Can you assist me with rivet selection?

    Sure, the Aerobolt team can assist with the selection by either calling us on 02 9755 3747 or contact us.  

    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.

    Rivet Summary.

    Rivets offer superior fastening capabilities for both heavy-duty and light fabrication applications. A rivet in one form or another has been used by people for numerous centuries and it is hard to imagine a world without rivets. 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 or rivet label required for your project, be assured with a bit of planning your project will end up as 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 riveting requirements.

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