Be Careful About Relying on Magnetic Sweeper Strength Ratings, or Magnetic Field or Flux Density Quantifications

We get asked sometimes “what grade are your magnets” or “can you tell me the field or flux density of your magnetic products”.


In other words customers want specific information in regards to magnetic sweeper strength, some objective straight forward measurement they can compare from manufacturer to manufacturer. And this is completely understandable. But be careful.


Gauss is the most misunderstood term in magnetics, greatly misused by some manufacturers who use the manufacturer’s Gauss rating to indicate the strength of their products, when in truth the strength of a magnet depends on:


a) Strength of the material (manufacturer’s Gauss rating)
b) Size and weight of the magnet


For example: The earth’s magnetic field is 0.5 Gauss and a refrigerator magnet is 10 Gauss.

Considering only these numbers one would think that a refrigerator magnet is more powerful than the earth. This of course is incorrect, the earth, due to its immense size is immeasurably more powerful.


If you are comparing products by their Gauss measurement.  You need to be concerned about the Gauss measurement at the distance from the magnet that you are picking up debris from.  If no distance is given, it’s usually referring to the Gauss measurement on the surface of the magnet.  But as we see in the example of the refrigerator magnet vs the earth, it’s not the Gauss measurement on the surface of the magnet that you should be most concerned about, it’s the measurement at the distance you will be picking up debris from.


Look for these measurements on Bluestreak’s product pages.  Bluestreak also provides the type and grade of magnet used, you can find this information on the individual product pages, usually in the specifications section.


We don’t measure “strength” of a magnet in terms of the “weight” of steel it will pick up, because it matters what the form of the object is that is being picked up. A steel bar is dense and you can pick up a lot more weight in terms of a steel bar, than you can nails, etc.


We have also attempted to come up with a way of communicating magnet strength that everyone would practically be able to relate to and understand, which is why we use the “maximum lifting height using a two and a half inch standard nail” measurement.


These measurements can also be found in the specifications section on the individual product pages.