I have used a couple of online calculators to estimate the attractive force between two cylindrical bar magnets. Using d=1"; t=1"; x=0.1"; Neo35 (Br=12,300 Gauss):
source 2 explains data is based on measured data, so this accounts for the difference from source 1. But in general, I think this is the right ballpark number.
I then tried to reproduce these numbers myself, using a formula I found on Wikipedia. I could not get close to the right answer - my answer is about 4000 lbf. Could someone please explain what I did wrong in my calculation?
EDIT Tough crowd. Let me try and be more specific.
The problem itself is pretty straightforward. I did not really mean to imply I need someone to check the numbers. I mean more on if I am applying the right approach to the problem:
Is the formula above valid when trying to replicate results in the calculators I linked? (i.e. "Calculate the Pull and Repulsion Forces Between Two Disc Magnets")
Perhaps "real life" is significantly different than theory for this application? In which case, the engineering calculators would apply a de-rating factor that is not represented in the Wikipedia formula. I did find any references to this, but perhaps someone with more knowledge could advise?
Assuming the formula is valid here, I think Magnetic Flux Density (B_0) is the most likely source of my error. It is my understanding that this is a physical property of the material. Is that correct? The value I found for Neo35 is Br = 12,300 Gauss (CGS units). I converted this to SI 1.23 Tesla using a 10^-4 conversion factor. Is this the correct interpretation of B_0?