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22 Parts of an Excavator and Their Functions

22 Parts of an Excavator and Their Functions

If you’re learning how to use an excavator, understanding its various elements will help you succeed at any job. So what are the parts of an excavator? While they can differ slightly between models, you’ll find the same basic components in any excavator, whether you’re working with a mini or a skid steer.

When it comes to understanding all the parts of an excavator, they can easily be broken down into three main sections: the undercarriage, cab and arm/boom. Let’s uncover the parts of an excavator and their functions!

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The excavator undercarriage is the bottom section of an excavator that houses various moving parts.

1. Excavator Tracks

The tracks of the excavator, typically made with steel-reinforced rubber, move the machine. Some excavators are wheeled but function similarly to those with tracks.

2. Track Frame

The track frame is where the excavator tracks attach to the undercarriage, functioning similarly to axels.

3. Track Pad

Track pads can help prevent excess noise, vibration and damage, as well as provide better traction during operation.

4. Track Chains

Track chains are what allow an excavator to move efficiently. They function similarly to bicycle chains in that they’re made up of connected flexible links.

5. Track Shoes

If you imagine the tracks of an excavator, the track shoes are the individual parts of the track that dig into the ground and pull the excavator along.

6. Track Bolts

Track bolts link each track shoe together to form the entire track.

7. Rock Guards

Rock guards are exactly what they sound like — they attach to the tracks of your excavator to protect the machine from debris and stray objects.

8. Sprockets

Sprockets are the mechanisms that run between the excavator track chain links. They behave like a giant bicycle sprocket, moving the chain along to propel the machine.

9. Rollers

Rollers are the metal wheels on an excavator undercarriage used to align the chains and move them between the sprocket and idler. There are two sets of rollers — bottom and top — to facilitate chain functionality.

10. Idlers

Bigger than rollers, idlers are large metal wheels within the undercarriage that help guide the excavator tracks. Idlers are the final mechanism that keep tracks running smoothly, along with the rollers and sprockets.



You might know it as the house or the car body, but the cab is the mission control of an excavator. This is where you’ll operate the excavator and keep track of some basics. Cabs can often turn 360 degrees for max visibility, depending on the model you’re using. Within the cab, you have your main control mechanism, which will vary from model to model, as well as the following components.

11. Main Controls

This will vary depending on the machine, but this is your mission control of the excavator. This is where you’ll find the excavator’s basic controls, steering mechanisms, safety measures and more.

12. ROPS

ROPS stands for “rollover protective structure” and is an important safety feature. It’s meant to protect the operator in the event of a rollover.

13. Counterweight

The counterweight does exactly what the name implies — it counterbalances the excavator when digging, providing leverage and preventing the excavator from tipping.

14. Engine

The heart of the excavator, the engine is typically housed near the cab so it’s easy to access for maintenance. It’s typically powered by diesel fuel.

15. Hydraulic Fluid Tanks

As many excavators are controlled with hydraulic mechanisms, the tanks themselves are housed in the cab.

16. Fuel Tank

Exactly what it sounds like, this is where the excavator’s fuel (as mentioned above, typically diesel) is stored.

17. Main Control Valve

The main control valve connects the engine and the hydraulic mechanisms, controlling oil pressure and powering hydraulic devices like the arm and boom.



Finally, on to the digging mechanism itself. The boom and arm work together to do the actual earthmoving work.

18. Boom

The excavator boom is the front part that’s attached to the cab itself and holds the arm.

19. Arm

Sometimes referred to as the dipper or stick, the excavator arm is attached to the boom and holds the bucket. Together, the arm and boom can manipulate the bucket and get everything into position.

20. Bucket

The bucket is the digger on the end of the arm, responsible for all your earthmoving needs.

21. Cylinders

There are typically three types of cylinders on an excavator: boom, arm and bucket. The cylinders connect between each section and are responsible for articulating each. For example, the bucket cylinder connects between the arm and the bucket, and helps move the bucket back and forth.

22. Attachments

Finally, there are a number of attachments you can add to your excavator. This will vary depending on your project needs. Some excavator equipment attachments include:

  • Rotators for the bucket
  • Brush cutters and mowers
  • Stump cutters
  • Boom extensions
  • Augers
  • Breakers and hammers
  • Tree shears
  • Pipelayers
  • Grading buckets


Frequently Asked Questions

Here are some of the most common queries about the parts of an excavator.

How many parts does an excavator have?

The exact number of parts will vary based on the type of excavator you’re looking at, but you’ll see the 22 listed above most often.

What is the end of an excavator called?

The end of an excavator is called the bucket, which is used to dig into the earth and scoop it up.

What is the arm of an excavator called?

The arm of an excavator is commonly referred to as the arm, dipper or stick.

How many types of excavators are there?

There are seven types of excavators that can be used for a variety of projects.

Ready to start digging? Now that you know the basic parts of an excavator, you’ll better know how to operate the best machine for your project. Try renting for a cost-effective option.

Explore All Excavators

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