Magnetic Detection of Ferrous & Non-Ferrous Metals

Identification of ferrous and non-ferrous metals: Utilizing Magnetic Locators to identify multiple types of utilities IE… Well casings, Septic tanks, Manhole covers, Iron pipes, Survey/Omni markers, Valve boxes, Steel drums, and Fuel storage tanks, Etc.

magneticDetect_1_largemagneticDetect_3_largemagneticDetect_2_largeNote: The following link for a technical manual providing overview and product applications:
           Magnetic Locator Model GA-72Cd (pdf)


Magnetic Locators will ONLY locate metal objects that are made of ferrous material. Basically speaking, if a magnet will stick to it, a Magnetic Locator will detect it. Understanding that how deep in the ground you can detect something depends on its mass. A surveying nail can be found up to about 2’ – 3’ feet. An underground storage tank can be found up to about 15’ – 17’ feet deep. Magnetic Locators will not detect objects such as electrical power cables made of aluminum or copper, since these materials are not considered ferrous. Items that are found using Magnetic Locators are usually cast iron pipes, property corner markers, steel enclosures or hardware, hazmat drums, mag and pk nails, manhole covers, marker magnets, septic tank lids, unexploded ordnance, valve boxes, weapons, and well casings.

  1. Ferrous Metal is any metal that can be attracted to a magnet. This is iron and steel. In time it will rust when exposed to air and water. Ferrous metal is typically the easiest metal to detect and usually the most common contaminant in industrial environments. Examples include paperclips, thumbtacks, pins, staples, most screws, nails, washers, welding slag, rust, abrasions from metal to metal contact, and tools dropped into the conveyor.

  2. Non-Ferrous metal is non-magnetic metals (copper, aluminum, brass, lead, etc.) It will take approximately 50% more of a non-ferrous metal to be as detectable as a ferrous metal. Manganese is also a non-ferrous metal and difficult for most metal detectors to detect. MDI’s digital flat and surround systems are very effective in detecting manganese.

  3. Stainless Steel is always the most difficult metal to detect due to its poor electrical conductive qualities. By definition stainless steel has low magnetic permeability. A stainless steel sphere would have to be 50% larger than a ferrous sphere to produce the same signal strength on the metal detector.


See these pdf document resources for more info.

For more information and details on how to put CNI Locates magnetic detection to work, call (877) 826-1177

Request a Free Estimate