Shear Nuts - Tamper Proof Security Nuts
Breakaway Nuts Designed to Prevent Tampering
Shear Nuts are conical nuts with coarse threads designed for a permanent installation where preventing tampering with the fastener assembly is important. Shear nuts get their name because of how they are installed. They require no special tool to install; however, removal will be challenging, if not impossible. Each nut consists of a conical section topped by a thin, threadless standard hex nut that snaps or shears off when the torque exceeds a certain point on the nut. The finished result resembles a Tri-Groove or Trident Nut, only it does not have the grooves for installation or removal.
Shear Nuts are commonly used on signs in hospitals, public spaces, playgrounds, schools, and correctional facilities to secure various equipment and protect against unwanted removal.
18-8 or 304 grades of Stainless steel are suitable for many general purpose applications, especially freshwater and non-salt water wet environments. Corrosion-resistant and durable, 18-8 stainless steel is equivalent to the A2 grade of stainless steel.
Zamak Zinc Alloy
Zamak is a zinc alloy family. The most common, Zamak 3, is an alloy of zinc and aluminum and the de facto choice for die casting. Zamak alloy has an excellent balance of physical and mechanic properties, superb castability, and long-term dimensional stability.
How to Install Breakaway Shear Security Nuts | Fasteners 101
How to Install Breakaway Shear Security Nuts Transcript
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Bob: Welcome back to Albany County Fasteners - Fasteners 101. I'm Bob and today I'm going to demonstrate to you a breakaway security nut.
So, I have here a breakaway security nut. Basically, it has a nut welded or it’s an integral part, not even welded, of the process when they made this. There is a weak point right here at the neck. As pressure gets put on the nut sides to tighten it, that will break away from the security cone nut.
Now this is almost the same thing as a tri-groove nut but doesn't have the tri-grooves in it to be able to remove this nut down the road. There'll be only one way to remove this nut. You're going to have to take an abrasive and you have to cut the ends or put some type of groove in it that you can get a flat head screwdriver in it or a vise grip around it.
So I’m going to demonstrate this now - the installation - and how it breaks away. We're going to put a carriage bolt in here. I'm going to hand-turn this on, like that. I'm gonna snug it up. Now, this is for demonstration purposes.
These particular breakaway nuts are used a lot in street signs. So, go out in the street, look at the signs you'll find them there. They come in stainless steel. They also come in zinc. I don't know if they come in hot dipped galvanized; not sure about that. But check our site. If they're available, we have them up there.
I have this snug right now on this piece of steel and I'm going to start to tighten it. Once it reaches to a certain pressure it's going to break and you're going to watch that happen right here. Okay I'm just going to turn it and it's tightening, and the other side is turning on me so I'm going to hold it and now it's gonna pop off. And that's what you have when you're all said and done.
This is the nut (hex) part that snapped off. Now you're not going to get this off. Unless you use a grinder with an abrasive and you cut grooves in it and then take it off with a wrench. So it's a process.
Thanks for watching.
Uninstalled Nut - Thread the nut onto the bolt or stud that you will be using it on.
Tighten with a Wrench or Socket - Using a wrench or socket, tighten the hex portion of the nut until it reaches the optimal torque and snaps off.
Finished Installation - After the hex portion snaps off, ony a tapered circular nut remains. Due to its shape, it cannot be grabbed by a wrench socket or gripping devices which makes it highly resistant to tampering or vandalism.
How to Remove Breakaway Shear Security Nuts | Fasteners 101
How to Remove Breakaway Shear Security Nuts Transcripts
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Bob: Welcome back to Albany County Fasteners - Fasteners 101. I'm Bob and today I'm going to demonstrate to you how to remove a security nut. So, let's get started.
I have my cordless grinder with an abrasive wheel on it and I'm going to cut a groove on this side and the other side, so I can get a wrench onto this security nut that's made so you can't get anything on it.
No matter what you do, you can't grip it, so we have to create something to grip it. So, we're going to cut the edge there a little bit to flatten it out and see how we do. Here we go.
I did one side over here. I'm gonna do the other side now. Make sure you wear protection. You must have eye protection.
As you can see there, it's cut so we can get a wrench on it. That only took me about a minute - minute and a half. I'm going to stick a vise grips on it and we're going to turn it. There it is. I've taken it off. Took me a couple of minutes just to get it off.
That's how you would remove a security nut without any groove to use the tool on it. Thanks for watching.
What are tamper-resistant nuts?
Tamper resistant nuts, otherwise known as security nuts, are pieces of hardware that function as a standard fastener nut. However, they are designed to be difficult, if not impossible, to remove unless a specific driver or heavy tools are used. They're used for anti-theft applications.
How do you remove security shear nuts?
Shear nuts are not designed to be removed. If they were, they wouldn't make very good security nuts! That being said, if they must be removed, one option would be to use a grinder and cut grooves into the sides of the shear nut so that you could grip it with some pliers or vise grips.
What is a shear nut?
Shear Nuts are conical nuts designed for a permanent installation where preventing tampering with the fastener assembly is important. The conical section is topped by a thin, threadless, standard hex nut that snaps or shears off when the torque exceeds a certain point on the nut. This leaves behind the conical nut, which is very difficult to grip and remove.
How do shear nuts work?
The conical section of the shear nut is topped by a thin, threadless, standard hex nut that snaps, shears off, or breaks away when the torque exceeds a certain point on the nut. This leaves behind the conical nut, which is very difficult to grip and remove.
What is stainless steel good for?
Stainless steel is good for general purpose applications, especially those involving water or freshwater. Suppose you need stainless steel for more corrosive environments, such as marine or salt-water applications. In that case, we recommend the 316 grade of stainless steel.
What is Zamak used for?
Zamak is used in many applications such as plumbing fittings, zippers, staplers, handles, locks, die-cast toys, sheet metal tooling, automotive parts, and some firearms, to name a few.