Do Bolts Need Washers?


When putting together furniture, you have probably come across a bunch of bolts, nuts, washers, screws and even more within the kits that they send you to put together the furniture. These kits come with a lot of pieces and can, at times, make you feel a tad overwhelmed.

So are all these pieces necessary to put the furniture together? Or is it overkill and they just want you to feel like it is a higher quality piece than it actually is? So let’s tackle one of the questions you may be asking yourself in this situation. Do bolts need washers? Bolts do not NEED washers, but they are highly recommended. Washers help distribute the pressure of the nut evenly over the surface so it isn’t damaged and also ensures the nut is pressed against a smooth surface, thus helping reduce the chance it will come loose.

If you want to find the best Bolts and Washers, click here.

So now that we know that washers are not 100% necessary to use on bolts, but help highly in keeping the integrity of the build, let’s dig into some details.

What are Bolts, Nuts and Washers?

Bolts, nuts, and washers are often the three amigos and used together. So let‘s dig in the detail of what they are:

  • Bolt: A mechanical fastener with a threaded shaft.
  • Nut: A small flat piece of metal, typically hexagonal or square with a threaded hole through it for screwing on to a bolt as a fastener.
  • Washer: A thin plate, typically disk or square shaped with a hole in the middle. Placed between the bolt and nut to help distribute the load of the fastener.

When using one of these in your project it is important to have all three of them. They are the perfect team to ensuring objects are tightly snug and can’t come apart from each other.

Why Use Washers?

Washers are the side kick to the nuts and bolts. They help protect the joint surface from damage during the tightening process and to distribute the load under the bolt head and nut according to the bolt science (https://www.boltscience.com/pages/why-use-washers.pdf). Thus the washers make the threaded fasteners they are used with become more reliable.

If you skip using washers it can dramatically reduce the length of time your object will be held together. This leads to the integrity of the build being hurt.

Types of Washers

There are multiple types of washers that can be used effectively depending on the need of the project. Let’s dig into some of them and what they are typically used for.

Flat Washers

These are commonly known as your plain Jane washers. The purpose of these washers are to increase the bearing surface of a nut or fastener head, which will in turn distribute the fasteners load while reducing heat and friction during the tightening process. They are also used as spacers and provide electric insulation in some cases.

Flat washers are most commonly used for general manufacturing, maintenance and repair type projects.

Lock Washers

The lock washer is used for fasteners that you may worry about rotating or losing friction because of vibration or torque. These washers prevent the nuts and bolts from turning, slipping, and coming loose because of those worries.

These washers are mostly used in automotive and aerospace industries because of the high vibrations. Even household appliances, like washing machines, use them. Pretty much anything that may vibrate will have some lock washers in good use.

Tab Washers

A type of lock washer, this washer has a single tab or multiple tab notches that form to shape around the bolts and nuts. Tab washers are used in harsh environments and can last in extreme heat and vibration situations.

Aerospace and medical industries commonly have tab washers in their products.

Shoulder Washers

Shoulder washers are used as a bushing to insulate fasteners or shafts within electronic equipment. These washers are made of non-conductive materials because of this common use.

Countersunk Washers

This washer looks like a kitchen sink with the bottom cut off. These washers allow flat or oval head countersunk screws to be installed flush within the surface. These are often used in consumer appliances, cabinetry and furniture.

Might be the most common washer when putting together furniture from the internet.

Spring Washers

This type of washer provides axial load to fasteners in case of vibration and thermal expansion to limit movement. Usually metallic and perfect for applications that require a degree of flexibility.

This is why the aerospace industry often uses spring washers in actuators on airplanes, including the flight controls and landing gear.

Using Washers

If you have finally decided that you are going to use a washer with your fastener, there are some factors you need to know when picking the right one.

  • Thickness: You need to make sure you have the right thickness of the washer. The thicker it is the tighter the fit.
  • Greasing: Sometimes you may want to grease your washer. The reason being, this will reduce the risk of corrosion, make it easier to put in place, and even make it more watertight (important if you’re trying to stop a leak).
  • Size: Measurement of the correct size is critical. Using a washer that is too small or too big will result in poorer tightness and effectiveness.

If you want to get the most out of your fasteners, then you should always keep in mind the benefits of washers. You may not think they are important, but they will truly benefit any application.

Final Thoughts

Washers are a vital component of tightening any fastener. They are not necessary but will add lifespan and integrity to any project that requires nuts, bolts, or fasteners. I would highly recommend to always use a washer in any tightening project.

Don’t forget there are many types of washers that come in different sizes and thickness. So when determining the best washer to use on your project, make sure you are choosing the right one for the job.

Related Questions

Do nuts need washers? Nuts do not NEED washers, but they are highly recommended. Washers help distribute the pressure of the nut evenly over the surface so it isn’t damaged and also ensures the nut is pressed against a smooth surface, thus helping reduce the chance it will come loose.

Does a flat washer or lock washer go on first? The lock washer goes into the threaded fastener first, then the flat washer. This ensures the lock washer adds tension to the fastener assembly.

What happens if you don’t use a washer?  Failure to using washers can dramatically reduce the lifespan of how your product is put together.

Should a washer go on the nut side or the bolt side? The washer should always go on the nut side. This will ensure that if the bolt needs to be loosened it will have enough room to have an easy release.

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