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What are Arbor Bolts?

This is a close look at a cog wheel and a bolt with thread.

You’ve probably got more than one type of bolt floating around int he bottom of your toolbox. You might have a few in your tool drawer. Heck, you may have one in the spare change holder in your car.

There are all kinds of bolts and you can find them in all kinds of places because they have so many uses. But one bolt you probably won’t ever find floating around at random is the arbor bolt. In fact, if you see this bolt floating around loose then something might be seriously wrong. So you’d better know how to recognize arbor bolts and know what they do. 

This bolt is very different from all those others when it comes to how it’s used, but you’d never know it to look at it. Arbor bolts look pretty ordinary when you see them. In fact, you may never know how absolutely necessary they are and how difficult it can be for some people when they need one.

Once you know what the arbor bolt does and how to get them when you need them, you’ll be an expert on this rare, incredibly unique little piece of hardware that’s much more essential than you ever knew.

Related: All Types of Bolts | Rock Bolts | Shoulder Bolts | Lag Bolts | Carriage Bolts | Anchor Bolts | Hex Bolts | Elevator Bolts | Hanger Bolts 

Recognizing Arbor Bolts

You might not recognize an arbor bolt if you saw it sitting somewhere by itself. This bolt has a very specific propose and specific use. When an arbor bolt is doing its job, you won’t really notice it at all and it definitely won’t be sitting on its own. The arbor bolt is an absolutely essential piece of hardware that’s very widely used and yet still not at all well known. In fact, nothing in construction could possibly be the same without them. 

Arbor bolts differ from other bolts because they come pre-assembled. All arbor bolts have a washer that’s permanently attached at the tip of the bolt. Right away, the attached washer gives the arbor bolts a very distinct look. These bolts also have a head with a sunken design that creates a distinct ridge around the head of the bolt.

Commonly, arbor bolts are made with a dark or black finish. They’re also made with reversed threads. When you look at the shaft of an arbor bolt, it looks as though it’s backward because it has a thread pattern that’s the reverse of other types of bolts. This reverse thread is very important and goes to the main function of the arbor bolt.

With all these distinct characteristics, arbor bolts should be easy to identify. But you’ve probably been surrounded by arbor bolts for years and just never knew it. When you see arbor bolts, you’ll usually only see them as part of something else. Most of the time, you won’t even notice that they’re there. But you will definitely notice if they aren’t! 

Using Arbor Bolts

This is a close look at an arbor bolt that holds down a metal sheet.

Arbor bolts are not used to hang furniture or hold it together. They’re not used to mount anything and they don’t hold machinery together. These bolts have one incredibly specific use, but it’s a pretty important one. Though arbor bolts only do one thing, you’ll find that it’s something you can’t do without if you ever end up breaking an arbor bolt.

Unlike other types of bolts, arbor bolts are not commonly sold at hardware stores. You won’t typically find these bolts on the shelf along with anchor bolts, carriage bolts, and all those others. That’s because arbor bolts aren’t like any other type of bolt. Most bolts are fasteners. Arbor bolts aren’t traditional fasteners. These bolts serve a very specific purpose and that’s why you can usually only purchase them in a very specific way.

Arbor bolts are specifically made to be used with power tools, usually miter saws. These bolts keep the tool secure and keep the blade in place. Arbor bolts are essential for keeping these saws working correctly and safely, and that’s why these bolts play such a huge role in so many different home improvement and construction projects. Because arbor bolts are only used with tools, these bolts are not generally sold in stores like ordinary bolts. Arbor bolts are sold by tool manufacturers as replacement parts. 

If you break or damage an arbor bolt that’s keeping your saw secure, stop using the saw immediately. Examine the tool to find out its make and model. With this information, you can look for a replacement anchor bolt. Because these bolts are so essential, all tool makers carry replacement bolts. You absolutely don’t want to operate a saw with a damaged or broken anchor bolt. Because the bolt holds the blade in place, operating a saw with a compromised arbor bolt is a huge safety risk. 

Make sure you get the exact arbor bolt you need for the tool you’re working with. Arbor bolts are made in very specific sizes to precisely fit the saw itself. You’ll want to make sure you get the bolt that was made for the exact saw you have. 

Working with Arbor Bolts

Delta 1342989 Arbor Bolt

It’s a good idea to check your arbor bolt before you operate any electric saw (if the tool has an arbor bolt). If the bolt is loose, then the blade will also be loose. Keep the bolt tight and keep your saw safe to operate.

Make sure your saw is turned off and unplugged before you perform any kind of maintenance on the tool. The arbor bolt can be tightened with a socket wrench. This ensures that the blade is steady so you’re ready to work safely with a saw that will operate precisely as it should. The washer permanently attached to the arbor bolt is easy to grip with a socket wrench.

Even if you never realized it before, you may have worked with arbor bolts many times. You may have relied on them much more than you never knew. Now that you know exactly what these bolts do, you know how important they’ve been to the construction industry and to so many home projects. 

So the next time you get out your power saw, take a good look at the blade…or more specifically, the bolts that are holding it in place. Arbor bolts have helped to keep you safe and keep your tools functioning for a long, long time now. Maintain the arbor bolts on your tools to keep your tools working well,. That way, you can keep on going with all your home improvement projects and keep getting tasks done.