Do Magnets with Identical Specs Deliver Equal Suction? 4 Hidden Variables That Matter

In industrial, electronic, and household applications, a magnet‘s holding power directly impacts performance. While many assume magnets with equal grade (e.g., N52) and volume must perform identically, real-world tests show up to 30% variation in suction force. This guide reveals the critical factors behind these differences.

1. The Physics Behind Magnet Suction

The theoretical holding force formula:
F = (B² × A) / (2μ₀)
(B = flux density, A = contact area, μ₀ = vacuum permeability)

This proves suction depends on the square of flux density and contact area. Even with identical BHmax values, changes in shape or pole distribution alter B and A significantly.

2. The 4 Real-World Variables

1. Shape & Pole Distribution: The Geometry Effect

• Disc Magnets (e.g., D10×2mm): Radial field lines suit flat surfaces but decay rapidly.

• Bar Magnets