If you are in the market for a metal detector or already have one and are wondering what you can use it for, you might be wondering, “What type of metal do metal detectors detect?” The answer includes a wide variety, from ferrous metals like iron and steel to non-ferrous metals such as gold, copper, and aluminum.
Modern metal detectors are engineered with cutting edge technology that allows them to accurately identify different metals based on their electrical conductivity, magnetic properties, and size. Whether used in airport security, construction, or hobbyist metal detecting, the ability to detect specific metals is essential for enhancing security, uncovering hidden treasures, or improving safety.
At Garrett, we’ve been in the industry long enough to know exactly what types of metals can be detected and the challenges involved – we’ll walk you through it.
Key Takeaways
- Metal detectors can detect both ferrous and non-ferrous metals, including iron, steel, gold, copper, and aluminum.
- Detection works through magnetic fields and eddy currents triggered by metallic objects.
- Conductivity and magnetic properties determine how easily a metal is detected.
- Ferrous metals are generally easier to detect due to their strong magnetic response.
- Non-ferrous and alloy metals may require advanced detectors with adjustable sensitivity.
- Garrett offers industry-leading metal detectors for security, prospecting, countermine detection, and recreational use.
Understanding How Metal Detectors Work
Metal detectors work by generating a magnetic field and analyzing how that field is disrupted when it encounters a metallic object. Every standard metal detector includes a search coil, also known as a transmitter coil, which sends out a magnetic signal. When this signal hits a metal object, eddy currents are created, which in turn produce their own magnetic field. A receiver coil picks up this response and sends it to the control box where the signal is interpreted.
Modern detectors, especially the Pulse Induction detectors that we offer at Garrett, detect different metals at varying depths and even offer advanced features like customizable settings and improved detection capability. These detectors are used in everything from hobbyist metal detecting to walk-through metal detectors at government buildings and security checkpoints.
The Science Behind Metal Detection
Overview of Magnetic Field Principles
The magnetic field created by the transmitter coil is the core of how detectors work. When this field interacts with a metal object, the object’s conductivity and magnetic induction determine how strong the signal will be. Detectors that use low frequency ranges are better suited for detecting large ferrous metals, while higher frequencies may better detect small, non ferrous metal targets.
Role of Transmitter and Receiver Coils
The transmitter coil emits the magnetic field while the receiver coil listens for changes. These coils work together to locate metallic objects based on disruptions in the field. The receiver coil detects the signal produced by the eddy currents generated when certain metals respond to the magnetic field.
How Metal Create a Signal When It Disrupts The Field
When a metallic object enters the detector’s field, it affects the detectability by generating eddy currents based on its conductivity level. This creates a secondary magnetic field that the receiver coil picks up. The control box then processes this signal to help identify the type and exact location of the object, allowing users to detect specific metals more accurately.
Conductivity and Detection
Why Conductive Metals Are Detectable
Electrical conductivity plays a major role in how well metal detectors detect certain metals. High conductivity levels create stronger eddy currents, which generate more noticeable signals. This is why precious metals like gold and copper are easier to detect with advanced detectors using optimized sensitivity settings.
Signal Strength Differences By Material Type
Ferrous metals such as iron have strong magnetic properties and generally create powerful signals. On the other hand, non-ferrous metals like aluminum or brass may produce weaker signals due to lower magnetic permeability or low electrical conductivity.
Non-magnetic properties can also affect detectability, especially for materials like non-magnetic stainless steel, which can be difficult for standard detectors to detect.
Types of Metals Metal Detectors Can Detect
Ferrous Metals: Magnetic and Easy to Find
Ferrous metals contain iron and are characterized by their magnetic properties. These types of metals are highly reactive to magnetic fields, making them some of the easiest for metal detectors to identify. Common examples of ferrous metals include both iron and steel.
Why These Metals Are Easily Detected
Because ferrous metal materials respond strongly to magnetic induction, they produce a strong signal in both VLF and PI detectors. This makes them ideal for quick identification during metal detection, especially in environments like construction zones or airport security screenings.
Typical Use Cases
Ferrous metals are frequently encountered in security screening environments, including weapons, tools, and concealed metal objects. Detecting them at security checkpoints, whether at airports, courthouses, stadiums, or schools, is critical for identifying potential threats, ensuring public safety, and maintaining controlled access. Their magnetic properties make them highly detectable, allowing security personnel to respond quickly and accurately during screening operations.
Non-Ferrous Metals: Non-Magnetic but Valuable
Non-ferrous metals are those that do not contain iron. They are not magnetic, but many of them are conductive, making them detectable by metal detectors that offer advanced features and customizable sensitivity settings. Common examples include copper, brass, aluminum, and gold.
Detection Challenges and Common Behavior
While non-ferrous metal targets are often valuable metals, they can be harder to detect due to their low conductivity or non magnetic properties. Aluminum cans, for example, have lower magnetic responsiveness than iron. Gold is also a precious metal with low magnetic permeability, which means it requires a sensitive detector.
Alloys and Mixed Metals
Alloys are created by combining two or more metals to enhance specific qualities such as strength, corrosion resistance, or weight. The manufacturing process of alloys often affects how they respond to magnetic fields and electrical signals.
Magnetic vs Non-Magnetic Types
Stainless steel is a common alloy. Some types are magnetic (like ferritic stainless) and easier to detect. Others are non-magnetic and have low electrical conductivity, making them much harder for metal detectors to find.
Adjusting Detector Sensitivity or Frequency
To detect challenging metals like non magnetic stainless steel or other low conductivity metals, operators can adjust sensitivity settings or change frequency bands. This is particularly useful in security checkpoints where detecting all types of metal, regardless of their properties, is essential for enhanced security.
Explore Garrett’s Range of Industry-Leading Metal Detectors
At Garrett, we offer a full range of metal detectors designed for a wide range of needs, from high-security screening to gold prospecting and sport detecting. For security professionals, walk-through detectors like the Paragon, PD 6500i, and Multi-Zone are ideal for screening at airports, schools, and events.
Our handheld detectors like the Guide, SuperScanner V, SuperWand, and THD deliver dependable close-range screening for security personnel at checkpoints, public venues, and events. These compact devices help identify metallic threats quickly and accurately, making them ideal for supplemental screening in schools, airports, stadiums, and other controlled access points.
If you’re searching for natural gold or minerals, prospecting detectors like the Axiom, Axiom Lite, Goldmaster 24k, and AT Gold offer high sensitivity in tough ground conditions.
For hobbyists and treasure hunters, sport detectors including the Vortex Series, AT Series, ACE Series, and Pro Pointers deliver fun, accurate detection across parks, beaches, and fields. No matter the application, we have a trusted solution built for any environment and your goals.
Understanding What Type of Metal Detectors Can Detect
Whether you’re a weekend treasure hunter or part of a security team, understanding the types of metal that metal detectors can detect helps you select the right tools and techniques for the job. From common metals to valuable metals, knowing how metal detectors work ensures you never miss a target.
Metal detectors play an essential role in identifying metallic objects across a wide range of applications. By understanding how metal detectors work, the science behind detection, and how different metals behave under magnetic fields, users can optimize their detecting experience, whether they’re scanning for hidden treasures, enforcing security measures, or identifying debris.Whether you’re securing a stadium, prospecting for gold, or scanning for threats at public events, Garrett offers industry-leading metal detectors built for precision and reliability. From ferrous to non-ferrous targets, our advanced metal detectors deliver reliable performance. Contact us today if you need help selecting the right detector or have any questions.
