Stainless steel is a non-ferrous alloy, which means it has low electric and magnetic permeability. As a result, it is among the most difficult alloys to detect by metal detectors, meaning that stainless steel generally does not set off metal detectors.
What Is A Metal Detector?
A metal detector is an electronic device that that senses the presence of metals. They can find hidden metal objects in public spaces and underground. They work by having a sensor that emits an electromagnetic field and creates an alarm sound when it comes across metallic objects.
What Metals Can Be Detected By A Metal Detector?
Metal detectors easily detect ferrous metals.
These metals contain iron or iron components, and their magnetic and electric properties are active, which makes them easy to detect.
Here’s the list of metals that a metal detector can detect:
- Carbon steel (where carbon is the primary alloying element and may contain other elements)
- Cast iron
- Wrought iron
Metals That Can’t Be Detected
Metal objects that are too thin or soft go undetected by metal detectors. Usually, metal detectors do not pick up jewelry, which includes gold, silver or platinum, if they are really small in size.
However, there are metal detectors capable of picking up many types of metals. The process of making a detector pick up different target metals is called discrimination. For instance, an audio-type discriminator can be programmed to emit sound signals to pick up metals like nickel.
Further, detectors do not detect non-ferrous metals easily because of the low magnetic field they produce. Since Titanium is a non-ferrous metal, it does not trigger an alarm in the detector.
Stainless steel is the most difficult to detect because it has very low electric and magnetic properties. Thus it fails to respond to the field created by detectors.
Does Stainless Steel Set Off Metal Detectors?
Stainless steel has very low electrical conductivity and low magnetic properties. So airport metal detectors usually don’t detect stainless steel easily. That said, some metal detectors will have the capacity to detect stainless steel if their sensors are configured correctly.
A metal detector produces an electromagnetic field around it. The field energizes any metal plate material in the region of the detector. Since stainless steel does not conduct electricity well, it fails to get energized by the field. As a result, the detector is unable to detect it.
Ferrous metals are those which contain iron or iron components. They conduct electricity well and have good magnetic properties. So these are easy for detectors to pick up.
Non-ferrous metals contain no iron and are non-magnetic. Some examples include copper, aluminum, lead, brass etc.
What is the difference between Steel and Stainless Steel?
Carbon steel and stainless steel are the two major types of steel. The former is more generally referred to as steel and may come in various forms.
Carbon steel includes a large number of steel alloys containing iron and 0.12 to 2% carbon. Within this short carbon content range, the steel varies significantly in terms of properties, especially hardness.
High carbon steels show excellent hardness, and abrasion resistance, allowing them to stand high magnitude forces.
Stainless steel, on the other hand, contains carbon, iron, and 10.5% chromium. More elements, like nickel, molybdenum, and manganese, can add further mechanical and corrosion resistance properties.
Chromium is the crucial component of stainless steel because it forms a layer of oxide that protects its surface from corrosion. Further, the same layer protects stainless steel from rusting.
Do Body Piercings Set Off Metal Detectors?
Body piercings do not trigger metal detectors.
Will an Artificial Joint Set Off a Metal Detector?
A majority of artificial joints and implants (such as what’s used in a hip replacement) will set off a metal detector. Nowadays, many orthopedic implants contain plastic and ceramic in addition to metals. So the metal will mostly raise the alarm of the metal detector.