Rivet Size Guide
Tri-Fold Exploding Rivets
Tri-Fold Rivets are a special kind of rivet. They are often referred to as exploding rivets due to the way they expand, but they may be known by other names such as tri bulb, tri tite, bulb tite, and olympic rivets. These rivets have three notches cut into the body, or hat, of the rivet. They are installed much like a pop rivet, using a riveter to pull the mandrel towards the hat. As the mandrel is pulled in towards the hat, the three sections bend, forming three legs. These three legs hold tightly onto the installation surface. This mandrel then breaks off at the head, much like a typical pop rivet will.
Bulb rivets come in many varieties. Weathertight bulb rivets come with an attached EDPM (rubber) washer set at the hat's base. When installed, these hats push the washer into the pre-drilled hole forming a watertight seal.
Tri-grip rivets have added benefits in terms of strength and clamping as well. The three legs that protrude from these rivets are used to distribute pressure over a surface area better. This means more force can be applied to the material without causing damage to it. They also keep a larger portion of the mandrel inside of the body. This added material can help to cure the weaker shear strength of typical blind rivets.
Tri-fold fasteners are prized for their more considerable multi-grip capabilities. Due to how the legs are formed during the installation process, the rivet can grab the installation surface earlier, making its range much greater than that of a blind rivet. They also work very well where the back of the installation material is not flat. The legs on these rivets will conform to the edges of the material when pulled against it.
Tri-Fold Exploding Rivets are often used in the automotive, truck, and trailer industries, as well as in sporting goods, RVs, appliances, and plastic components. The Tri-Fold split tail creates three anchor points on the blind side of the rivet installation, which spreads the load over a wider area. This makes Tri-Fold Rivets ideal for use with thin metals.
Shaveable Rivets are a type of bulb rivet designed with an unusual mandrel. The mandrel on a shaveable rivet's mandrel does not break off entirely on installation. Instead, a portion of the mandrel is broken off and remains in the hat. Then, a rivet shaving tool is used to shave down what is left of the mandrel. This leaves a smooth head surface without the typical hole in the middle that is common on blind rivets.
Water Tight Shaveable Rivets
Watertight shaveable rivets have a built-in rubber (EDPM) washer attached at the base of the hat. As the rivet is installed, the rubber washer will be pushed against the hole it is installed into. The rubber will expand and fill the hole of any gaps to create a watertight seal. These are a common choice for RVs and trailers as replacements for the factory rivets that come loose from natural wear and tear.
Tri-folding Shave Rivets
Shaveable Tri-Fold Rivets Demo Transcript
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Bob: Welcome back to Albany County Fasteners - Fasteners 101. Today I'm going to demonstrate the installation and shaving of a shave rivet. Let's get started.
So I have here a piece of pre-drilled steel. I have a couple of shaved rivets. These are tri-fold exploding rivets. This particular rivet has a washer on it so, if you need waterproofing for a trailer, you can get them with the neoprene washer against the backside to prevent any leaking into the trailer.
I'm going to insert the rivet. I have my rivet tool and you don't install these like a normal rivet. You don't keep cranking the rivet tool until it snaps, but you do want to snug it up to the backside and I'm going to show you.
As you can see here, that's correctly installed. That is incorrectly installed. You can see that it's not totally up against the backside. So you want to make sure that you install the rivet properly so you have a nice tight fit.
Then I'm going to take my snips and then leave about a 1/2 inch and I'm going to snip these off. That's a little bit more than a half an inch.
I'm going to take my shaver, these shavers you have to select the correct bit along with the correct crown to shave off this mandrel properly. It's a little tricky so you have to learn as you go.
You just gotta go a little bit at a time. Can't just push down on it hard. That's it right there. Look at that! Very nicely finished. Nice-looking product.
That's your backside. That's your tri-fold, also collapsing as they say, because the rivet collapses on the backside and on the outside of your trailer or whatever your riveting for a finished look. That's the key there.
These tools are they range in price anywhere from, you know, two hundred and some odd dollars. Maybe $299 and they can go up to seven or even $1,000. I bought the cheapest one to be frank with you. This is $299. It does the trick, it's a good product.
Thanks for watching!
Dome Head Tri-Fold Exploding Rivets
Tri-fold exploding rivets with a dome head sit above the installation surface once installed. The hat's dome portion is rounded and provides a smooth finish after the mandrel is snapped off. Tri-fold rivets expand out in three directions as the mandrel is pulled into the hat of the rivet. These wings provide excellent hold against installation materials.
Dome head tri-fold rivets also come with an EPDM washer, which gets compressed against the hole as the rivet is installed. Once installed, the rubber washer fills any holes between the hat and hole of the rivet. This creates a watertight seal, making these rivets popular in RV, Kayaks, and automotive applications.
Recessed Crown Dome Head Tri-Fold Exploding Rivets
Recessed Crown Tri-Fold Rivets are similar to standard Dome Head Rivets but feature an indentation around the rivet's mandrel, which creates a neat, aesthetic finish once installed. This creates an overall lower profile head as well.
Low Profile Flat Head Tri-Fold Exploding Rivets
Low Profile Flat Head Tri-Fold Rivets feature a flat head to run nearly flush with the installation surface, creating a clean finished look.
Recessed Crown and Low Profile tri-fold rivets retain the mandrel's stem to provide a strong vibration-resistant joint.
Rivets are measured in installed grip range and length. The Rivet size guide above can assist you in finding the right size rivets for your application. For more information on rivet sizing and blind rivets in general, visit our Fasteners 101 page on the subject: Blind Rivets.
Not sure what material you need? Check out our Material Guide to find the right material for your needs!