In the last few months we’ve seen an unusual spike in requests to remove magnetic fields in manufactured parts. Most of the time these fields are created by some type of manufacturing process like milling, grinding, or turning. As the manufacturing processes continue, the stronger the magnetic field(s) becomes. Most of the time the magnetic fields induced go undetected and in a lot of cases, don’t pose any problems. If you notice shavings or grinding dust “clinging” to a part, it probably has a magnetic field that was induced by a manufacturing process. Transporting parts in a North or South direction can even induce magnetic fields.

So what’s the harm?
Parts manufactured for gear cases, rotating assemblies, bearings, or moving (rotating) metal to metal situations should have any magnetic fields removed. A magnetic field will attract metallic debris causing pre-mature wear and possible failure. In situations where oil is getting pumped or splashed for lubrication, a magnetized part will act as a filter, trapping and retaining metallic debris. With electrical components, sensors or safety switches in the finished product, a nearby magnetic field could cause problems that could be very hard to diagnose.

How would you know?
This is very simple; a device called a Magnetometer can detect magnetic fields. Also known as Magnetic Field Indicators or Gauss Meters, some of these are very sophisticated and some are as simple as a sundial. The smallest and simplest does not require any power source, no chord, no batteries, and basic training would take less than a minute. Checking a part with one of these also takes about a minute. If your Magnetometer is used for required manufacturing readings / reports, you’ll probably need to have it calibrated, if you have one for reference only, probably not. Check with your Quality Manager on this one.

How can magnetic fields be removed?
Give us a call…we’re experts. In processing one of the inspection methods we perform, Magnetic Particle, we induce magnetic fields, sometimes multiple fields in opposing directions. When the inspection work is complete, we remove the magnetic fields. Using a Magnetometer, we measure as we go to insure these fields are removed meeting specification requirements. We do this every day!

More questions?
Give us a call at 937-298-9390 or email Dan Reynolds, Technical Sales. American Testing Services sells and calibrates (ISO 17025) magnetometers, and we often have pre-owned, calibrated units for sale.  If you have parts that need to be de-magnetized, we can typically turn the work around in 1 to 2 working days.