Applied Magnets 1-pc, Grade N42, Strong NdFeB Neodymium Magnet Ring, 3" OD x 1/4" ID x 1/2". 1 Piece - Made with the Strongest Magnet - Neodymium Magnet. Offers much more holding power than any ceramic magnet. Magnet Grade N42 , stronger than N40, N38 and N35. Magnetized axially through the Thickness 1/2", poles on the flat surfaces. Approximate Pull Force: 165 lbs. Durable Nickel-Cpper-Nickel 3-layer Coated magnet.