what is a borescope

What Is A Borescope?

Like many other inspection tools, a borescope allows you to see places that wouldn’t be visible otherwise. When you inspect an item, you can insert a borescope without causing damage to that item.

There are several different types of borescope available. Different designs are optimized for different objects. But most of them are built with the same basic components in mind.

What Is a Borescope Used For?

Borescopes are used for a variety of applications, usually related to industrial machinery. Like an endoscope is used to see inside the human body, a borescope lets you see inside a machine.

You can use them to inspect systems like automotive and aircraft engines, manufactured parts, and other machines. When the tool is inserted into these materials, you can see the interior.

A borescope might be used to do any of the following:

  • Evaluate the condition of a piece of machinery or part of a machine
  • Evaluate the quality and security of a manufactured component
  • Check the inside of a piece of equipment for potential contraband
  • Evaluate the safety of a piece of machinery by checking for any danger signs inside

Borescopes might be used to inspect materials like internal combustion engines, turbine engines, welds, pipes, gearboxes, cast parts, and heat exchanger tubes.

They can also be used to locate, identify, and even retrieve foreign objects from inside a piece of equipment.

Borescope Inspection Procedure

There are four main uses for a borescope:

  • Hollow shaft inspection
  • Inspection of the shock absorbing spring
  • Detection of carbon in the combustion chamber of an engine
  • Gear box inspection

An industrial model can be used to investigate all of these components on an industrial level.

A borescope can detect carbon. When there is carbon in an engine, it has a negative effect on combustion. The engine is not able to generate as much power, so it consumes more fuel less efficiently.

By using a borescope, you can determine whether there is carbon in the engine without needing to disassemble it entirely.

Springs are often used in trains, industrial machinery, and other welding procedures. They need to absorb the shock of motion to keep the other pieces from wearing down.

Traditionally, shock absorbers could only be checked by taking the springs apart. But borescopes put an end to that and offered a means of non-destructive testing by remote visual inspection.

When you insert the borescope into the spring, the high-resolution camera will capture a feed of the cracks inside. You’ll also be able to see the top.

These combined factors will tell you whether the spring is still absorbing shock properly, or whether it needs to be replaced.

Gearbox inspections are done on trains. As trains get older, their gearboxes begin to wear down and become marked. Friction can even cause derailing of the gearbox if the issues aren’t discovered.

To inspect a gearbox, you can slip the guide tube into your oil port until it reaches the gearbox. This lets you see the interior of the machinery. You can detect foreign particles inside, take pictures, and make plans for future maintenance and replacement.

Hollow shaft inspections are also related to trains, usually high-speed electric models. If a shaft is tested and found to have corrosion or damage, you can use the borescope to get further information.

By inserting it inside, you can observe microscopic cracks and catalog the extent of the potential damage.

Some inspectors have video recording software built into their borescopes. This allows them to take a video of the interior and analyze it later using 3D software.

Types of Borescopes

Borescopes have come a long way in recent years. Regardless of the type, they tend to have four main components:

  • A flexible or rigid length that can be inserted into the machinery
  • A light source to illuminate the inside of the machinery
  • A camera or lens system to allow the user to see inside
  • A monitor or eyepiece to view images in real time

The three main types of borescopes on the market are video scopes, fiberscopes, and rigid borescopes.

Video Borescopes

Video borescopes or video scopes are outfitted with cameras. The camera sensor is placed on the tip of the tool. As the inspector uses the tool, it captures video and images on a monitor.

This screen can be recorded so that the images are easy to playback and analyze later.

The quality of the camera depends on the device. Some are able to zoom in to microscopic levels, giving people a view that they wouldn’t be able to get with the naked eye.


Fiberscopes use fiber-optic imaging guides. They transmit images from one lens to another. You can use an eyepiece to view the image or connect the tool to an adapter.

With an adapter, the image can be filtered through a CCD inspection camera so you can watch the video in real-time on a monitor.

Ridgid Scopes

Rigid scopes use basic lens systems to project from one lens to another. Like the previous model, these can be connected to a camera for viewing on a monitor.

Unlike the previous model, these tools are rigid or semi-rigid instead of flexible. They cannot be bent to fit a curved or irregularly shaped opening.

Final Thoughts

Borescopes are vital tools for inspecting machinery without needing to take it apart. When you insert them into different pieces of equipment, you can view the interior without any damage.

This allows you to identify areas of weakness, structural instability, or corrosion.

These tools are used by inspectors in a variety of different industries, from automotive, aerospace, and manufacturing. They also come with different viewing options.

Some have cameras that can pick up microscopic details. Others are rigid and immobile.

The best borescope for you is one that will fit into your machinery and give you enough data to evaluate its quality.