The “North” pole of a magnet defined by the National Bureau of Standards (NBS) convention is based on the following: “The North Pole of a magnet is that pole which is attracted to the geographic North Pole. Therefore, the North Pole of a magnet will repel the north seeking pole of a magnetic compass.” MCE follows this convention.
If you follow a convention that is different from the NBS convention, then you are probably using a compass to determine polarity. Following the compass rule would mean that you identify the “North” pole as that which would ATTRACT the north-seeking pole of a magnetic compass.
Notify us, when placing an order, if you follow a different convention. In the absence of a convention by the customer, MCE follows the NBS convention. We would like to maintain a record of the convention you use.
Once received, we will send an e-mail confirmation that this has been implemented for your organization.
If your parts are symmetrical such that the polarity does not matter, then of course it is not necessary to indicate the polarity, but if pole identification is required by marking, stating the convention used is necessary. In the case that the parts are not symmetrical, but you are going to get an even number of magnets, with half the lot magnetized one way, and the other half the other way, again it would not matter until you find that you need to get some magnets polarized only one way (an example would be if someone in your assembly department accidentally broke a couple of magnets that were a certain polarity). In this case, to get correct replacements, defining the convention being used is very important.
Do not confuse “orientation” with “polarity”. The orientation only gives the preferred magnetization axis, while polarity tells which pole will be at a specific location.
If you would like to receive the magnets unmagnetized, then only the orientation needs to be shown on the drawing. The drawing note must state “Supply Unmagnetized” or “Do Not Magnetize”.