Sometimes, customers will find the magnet information they need directly from online store and ask us to quote and make sample. For example, this German customer wrote in an email:
Thank you very much for sending the quotation. Please tell us the cost to produce 5 pcs samples of neodymium cup magnets in NdFeB N42 according to standard magnet technical specification attached.
The customer gave us the most complete information and it was reasonable that our samples should be fine, but we were told that:
We have tested the magnets. But it lacks 50% of the power which is needed of us.
Can you make new sample, that the magnet in the same size, but has more power?
We want to test these magnets: with magnet material N50, 5 PCS with H = 4,5 mm & 5 PCS with H = 5 mm, cost these samples like the last time?
So, we started making magnet prototypes again according to the N50 grade. But the second feedback was still a failure. In the end the customer sent us a sample with enough power they want, but with larger size.
Is it possible to make the magnet without changing the measurements with a stronger force?
We need the power of the sample we send you and the measurements of the samples you have send us.
Please make us new samples.
After receiving the customer’s sample, we measured it and found that the size was D20 and that the vertical pulling force was up to 16 kg. Given the large difference in pulling force, we confirmed some more information with the customer.
What is the grade of magnet for sample D20x6mm you sent us?
Can you accept changing d2 from 7.22 to 5.22mm or 6.22mm?
There will be no gap between magnet and steel cover, is this okay?
We started working on a new design after receiving the response that no grade information, fixed D2, and no gap is ok.
Due to the limited size, we optimized the interior design of the pot magnet, removed the gap between the magnet and the iron shell, and used magnets with different properties. After continuous professional simulation calculations, finally, the new sample achieved the pulling force of the D20 prototype while retaining the original dimensions D16.
This time the customer was finally satisfied with the sample’s pull force. But they also raised a new question:
The sample arrived us. Thank you very much. It looks like good and the improved design and stronger force are okay for us. Is it possible to make a little radius on the outer ring of the magnets. We have marked the point on the attached picture. It would be useful for us to have a radius 1.0 mm (chamfer) . Please speak with your people.
By calculations, we found that R1 will reduce some magnetic force. We think small chamfer (（0.3-0.5）x45°) can minimize impact on magnetic force as much as possible.
Kindly find the impact data of chamfer on magnetic force (analog computation) in attachment. It’s okay between 0.3 – 0.5×45°. Please confirm this.
The customer finally accepted our proposal and chose the third chamfer size 0.5 x 45°.
Thank you for your effort in this case.
The magnets arrived us and we had proofed magnets during the incoming goods inspection.
They are good. The Quality of the magnets which you delivered us is perfect.
Next Time I will send you a new order about the magnets.