NOTES:
1. The calculated pull force values are based on the assumption of pulling the magnet attracted on thick enough mild steel (low-carbon steel). Thick enough means all magnetic lines are contained in the steel. Normally 20mm thick is enough but still based on the magnet size.
2. The actual pull value may be less due to actual lower Br, thinner steel or different steel material used, gap present and high temperature. Therefore the calculated values are for reference when you design the magnet size.
3. Thickness direction is the magnetization direction.
NOTES:
- Magnetic flux density is also called “B field” or “magnetic induction”. It is measured in tesla (SI unit) or gauss (10,000 gauss = 1 tesla).
- Same as pull calculation, the actual measured B field may also be smaller than theoretical value due to actual lower Br, high temperature and the tolerance from measurement method. Sometimes there are coating or plating layer on the magnet surfaces. In this case we suggest counting the coating or plating thickness into distance Z value for more precise calculation.
Magnetic Field Lines for Rings
NOTES: In the inner hole and nearby, the magnetic field lines’ direction is opposite with outside ones’. It makes the value of the magnetic flux density (B) is minus as B is a vector.