FTM 194 – Part Numbers and standards of Blind Rivets

Everything you ever wanted to know about break-mandrel blind rivets, and how to decode rivet part numbers

This edition of the Fastener Training Minute with Carmen Vertullo was originally published November, 16th 2023 as “Everything you ever wanted to know about blind rivets” during episode 194 of Fully Threaded Radio.

Well hello everyone, and welcome to the Fastener Training Minute. This is Carmen Vertullo coming to you from Carver Labs in beautiful El Cajon California, and from the Fastener Training Institute.

Today’s topic didn’t really come from anyone’s question, it just turns out that I happen to be spending a lot of time in the lab lately testing break-mandrel blind rivets (also known as Pop rivets or nail rivets), and there are a few things to know if you are a fastener expert, or  consider yourself wise in the ways of fasteners and particularly blind rivets that most people don’t know. And I think that  you should know, so when we return I’ll give you a few Basics and a few things that go beyond the basics, when it comes to break -mandrel blind rivets.

Well welcome back everybody this is Carmen Vertullo with the Fastener Training Minute talking to you about brake-Mandrel blind rivets commonly called blind rivets or pop rivets

I’ve been doing a lot of testing of rivets lately and it occurred to me that some of the things that you have to know to test rivets, most people don’t know. I’m going to tell you that, but first I’m going to tell you all the common stuff that there is a know about blind rivets. First off, a blind rivet is what it sounds like: it’s a rivet that you can install from one side of the work. It’s got a body and it’s got a nail and you put it in a hole and hold two things together (or more maybe) with a tool: a hand tool or a Pneumatic tool or hydraulic tool or some kind of a tool to set the rivet. The mandrel pulls through the body, expands it on the backside, it breaks off and it sets pop pop pop – very nice actually. Very sophisticated fastener for not having any threads.

Now the first thing to know about blind rivets is that they come in different materials. The most common material that we see is aluminum. We have an aluminum body and an aluminum mandrel (or nail). and that part of the rivet (the material) is part of the part number. So if it’s an aluminum rivet with an aluminum nail we would call that rivet an “AA”  rivet for aluminum/aluminum. Various manufacturers use different configurations for their part numbers. That aluminum alloy rivet body can also come with a carbon steel mandrel. In that case, we would call it in an “AS” rivet for aluminum/steel. Now we also have a steel rivets and those steel rivets come with a steel mandrel only, because an aluminum mandrel would not be strong enough to set them, and that’s called an “SS” rivet steel/steel. And then of course we have a stainless steel, and stainless steel rivets come with stainless steel mandrels in which case it would be “STST” for stainless steel/stainless steel. They can also come with a carbon steel mandrel which makes them slightly cheaper, and that would be an “STS” or stainless steel body/steel mandrel. There are some other materials, but we’re going to leave those alone, copper nickel copper and so on. But mainly we’ve got aluminum/aluminum, aluminum/steel, steel/steel, stainless steel/stainless steel and stainless steel with a steel mandrel.

So that’s the first part of the part number: the material, And then there’s the size. Rivets come in different diameters and lengths and the diameters are measured in 1/32 of an inch and they are given numbers such as “3” for 3/32 of an inch and “4” for 4/32 of an inch (which is actually an eighth), and “5” for 5/32 of an inch, which is an odd duck (we don’t see a lot of those), and “6“for 6/32 of an inch (which is 3/16).  And then of course we would have “8”  for 8/32 (which would be a 1/4 diameter).

So now we have a diameter, so next there is a length which is actually the grip ranged length. It is measured in its maximum (the diameter of the rivets are measured in 1/32 of an inch off and the grips are measured in 1/16 of an inch) So for example 1/8 inch rivet with a 1/4 grip would be called a 44 rivet “4” for the diameter and “4” for the length. The length being measured in sixteenths of an inch, 4/16 being a quarter of an inch. Now we have a material and a rivet diameter and size, size sometimes called the rivet number.  So for example in 1/8 inch by a 1/4 inch aluminum/aluminum rivet would be a “AA44“.

One more feature of the rivet would be its head. The most common type of head is a dome head,  which looks like a button head. Another type of rivet head would be a countersunk head,  and then a another type of rivet head would be a large flange head.

So putting all that together we can get a rivet part number. So now we go with our rivet material let’s say it’s aluminum/aluminum and the head is a dome head we’re going to add a “D” into there somewhere. say “AAD“, and then we have a rivet number “44” for 1/8 inch diameter by 1/4 inch long “AAD44“. Now that’s the number scheme that I grew up with when I worked for a fastener distributor. And we made it up and it’s the best rivet part numbering system ever. Better than all the manufacturers systems which I think are more confusing. So you just basically have to know which products you sell, buy or use and how to use their part numbering system.

So that’s what everybody knows about blind rivets. You’re saying to yourself no kidding Carmen I knew all that.

So here maybe are a few things that you may not have known, and that is that all blind rivets have a standard that they abide by, just like most other fasteners, and the most common fastener standard for break-mandrel blind rivets is the IFI 114 for inch rivets. And we are going to stick with inch rivets for this Fastener Training Minute. We’ll do another Fastener Training Minute for metric or ISO rivets at another time. If you have your IFI book by the way in almost anyone even the older ones will work for this because they haven’t changed much, you should get it out and take a look at IFI 114 that’s where break-mandrel blind rivets come from. There’s also a really cool standard called IFI 110 which has the glossary of terms relating to blind  rivets.

We are not going to cover that because you can find out all about that in an FTI webinar on blind rivets (an old one or new one. I think we’re going to be doing a new one on blind rivet soon), and then are are lots of other miscellaneous standards that are take-offs on the standard IFI 114 break-mandrel blind rivets such as IFI 116 which is a multi grip,  and IFI 117 which is a self plugging in structural rivets is another three or four or five different ones. And then finally, well let’s stay in IFI 114 for just a minute because what I wanted to tell you that you probably didn’t know, is that these IFI 114 and all the other blind rivets have performance requirements as well. So we test them for four or five different things depending on the standard. We test them for their tensile strength after they are set. We test them for their shear strength after they are set . We test them for the strength of just the mandrel itself. We test them to be sure the mandrel will be retained in the body after the rivet is set. And we test them to make sure that the mandrel will be retained in the body while it’s still in the package so it doesn’t fall apart during shipping or before it gets used.  And there’s lots of details on those.

Now because we test them, it only stands to reason they have to meet some kind of requirement,  and now we’re going to introduce the concept of grade. There are many different grades of blind rivets , based on the material and so the performance would follow the material and the size.  The grades start at 9 and go to 54, but they skip a bunch of numbers  and  there really are about fifteen different grades,  but the most common grade is Grade 11   for an  aluminum/aluminum blind rivet. then we have Grade 19 for an aluminum body with a steel mandrel and there are several others in between. our steel/steel rivets are Grade 30,  stainless steel with a carbon steel mandrel is Grade 50, and Grade 51 is the stainless steel rivet with a stainless steel mandrel.

So there are six common grades 11, 19, 30, 50 and 51 with a bunch of others in between page on the other sides of that that you can learn about it the FTI webinar .

So those are the things about blind rivets I think that most people don’t know. They have a standard, or many standards, there’s a glossary, and there are tests that are required, and they have grade designations.

Well that’s about all there is to know right now about break-mandrel blind rivets that we can get into one minute. Maybe it’s been five minutes so far, I don’t know but I also encourage you very much to attend the next FTI webinar.

This has been Carmen Vertullo with the Fastener Training Minute, thanks for listening.

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