Thickness Gauge FAQs

What is a thickness gauge?

A thickness gauge is a device used to quickly and easily measure the thickness of a material. A thickness gauge is useful for many industries but is most commonly used in engineering and manufacturing to help ensure material thickness complies with industrial standards and regulations. As well as measuring the thickness of a material, a thickness gauge can be used as an additional quality assurance tool in industries such as automotive manufacturing to measure the uniformity of the material and may help identify hidden damages or imperfections.

What are the different types of thickness gauges?

There are several types of thickness gauges designed to measure different materials and applications. Ultrasonic thickness gauges, Hall-effect thickness gauges, and coating or paint thickness gauges are among the most common.

• Ultrasonic thickness gauges, or UT gauges, use high-frequency sound waves to measure the thickness of materials such as metals, plastics, glass, and most engineering materials. They can typically take measurements from just one side, making them useful for inspecting pipes, tanks, and structural components.
• Hall-effect thickness gauges measure non-magnetic materials using a magnetic probe and a target ball, disk, or wire. They are often used to measure thin materials like plastic and rubber when access to both sides of the sample is available.
• Coating or paint thickness gauges are designed to measure protective coatings such as paint, plating, or powder coatings applied to metal surfaces.

Each type of thickness gauge is suited to different inspection needs, which is why many industries use multiple measurement methods depending on the material and application.

How do ultrasonic thickness gauges work?

Ultrasonic thickness gauges measure material thickness by sending high-frequency sound waves into a material and measuring how long it takes for the echo to return. The probe emits an ultrasonic pulse that travels through the material until it hits the opposite surface and reflects back to the transducer. The instrument calculates thickness based on the time it takes for the sound wave to travel through the material and return. Because the measurement relies on sound propagation, ultrasonic gauges can measure many materials—including metals, plastics, ceramics, and glass—and typically require access to only one side of the test piece.

What are ultrasonic thickness gauges used for?

Ultrasonic thickness gauges are used to measure material thickness and detect corrosion, erosion, or wear without damaging the part. Using ultrasonic thickness testing, an ultrasonic thickness measurement gauge sends high-frequency sound waves through a material and calculates thickness based on the returning echo, enabling fast and accurate ultrasonic thickness measurement from a single accessible surface.

These gauges are commonly used to inspect pipes, tanks, pressure vessels, and structural components across industries such as manufacturing, energy, and infrastructure.

What are the benefits of thickness gauges?

Thickness gauges offer several advantages for quality control, inspection, and maintenance across many industries:

• Non-destructive testing: Measurements can be taken without cutting, damaging, or dismantling the material.
• Single-side access: Many gauges, especially ultrasonic models, measure thickness from just one accessible surface.
• Corrosion and wear detection: They help monitor wall thinning in pipes, tanks, pressure vessels, and structural components before failures occur.
• Improved quality control: Manufacturers use thickness measurements to ensure materials meet required specifications.
• Versatile applications: Thickness gauges can be used on metals, plastics, coatings, and other industrial materials.

These capabilities make thickness gauges essential tools for industries such as manufacturing, energy, aerospace, automotive, and infrastructure inspection.

How much does a thickness gauge cost?

Different factors can affect the price and cost of a thickness gauge, such as the transducer frequency, thickness measurement application, and software capabilities. We offer free quotes and demos so that you can test and evaluate gauges pre-purchase; contact us to learn more.

What is a Hall-effect thickness gauge?

Hall-effect thickness gauges, such as the Magna-Mike™ 8600 gauge, use a sensor that responds to changes in a magnetic field by varying a voltage. Using a small target ball, disk or wire , these gauges can accurately measure the thickness of nearly any nonmagnetic (nonferrous) material where a probe can be placed on one side and a target, like a steel ball, on the other. Hall-effect gauges are also called magnetic thickness gauges.

How do you measure pipe thickness?

If you’re looking to measure the thickness of a pipe, an ultrasonic thickness gauge should be used. A handheld thickness gauge, such as the 27MG , 45mg or 39DLP gauge, will offer accurate measurements from one side of metal pipes and parts that are thinning due to erosion or corrosion.

How do you measure metal thickness?

Metal thickness is commonly measured using ultrasonic thickness gauges, which are widely used for industrial inspection and maintenance. These ultrasonic metal thickness testers send high-frequency sound waves into the metal and calculate the thickness based on how long it takes for the sound to reflect back from the opposite surface. Because the measurement only requires access to one side of the material, ultrasonic gauges are ideal for inspecting pipes, tanks, pressure vessels, and structural components.

How do you measure steel thickness?

Steel thickness is typically measured with an ultrasonic thickness gauge, which is well suited for most metals such as carbon steel and stainless steel. Ultrasonic technology allows inspectors to quickly measure the remaining wall thickness of steel components, even if corrosion, coatings, or limited access make traditional measurement methods difficult. These gauges are commonly used in industries such as oil and gas, manufacturing, and infrastructure maintenance to monitor steel structures and detect material loss over time.

What is mil thickness?

A mil (or thou) is a unit of thickness that equals one thousandth of an inch (0.001 inches). Example: 10 mils = 0.010 inches. Mil thickness is commonly used in manufacturing in non-metric countries to measure the thickness of various thin materials, such as paint layers, thin films, foils, plastic sheets, and coatings.

What is micron thickness?

A micron (µm) is a small unit of thickness that equals one-millionth of a meter (0.000001 meters) and one-thousandth of a millimeter (0.001 millimeters). Micron is the shortened word for micrometer and is the closest metric unit to a mil (25.4 microns = 1 mil).

How do you measure paint thickness?

Ultrasonic thickness gauges can measure paint thickness nondestructively. For example, high-frequency thickness gauges such as the 72DL PLUS instrument offer features that can calculate total paint thickness and simultaneously display paint thickness measurements of up to six individual layers. Paint thickness is typically expressed in mils or microns.

How do you measure plastic thickness?

To measure the thickness of plastic nondestructively, a Hall-effect or ultrasonic thickness gauge should be used. The thickness of plastic is often expressed in mils or microns.