The size of a cup magnet is given by specifying the Outer Diameter x Inner Diameter #1 x Inner Diameter #2 x Thickness. Like discs, most rings are magnetized through their thickness so that the north pole is on one flat surface and the south pole is on the opposite flat surface.

Cup magnets are countersunk ring magnets set inside steel cups. The steel protects the magnet and controls the magnetic field, with the front side being stronger and the backside being weaker than the same magnet without the cup. The countersunk hole works great with screws or bolts.

Cup Magnets

Sort by:     Model     Product     Price      Default     See details 16 x (6.5x3.5) x 5mm N38 Nickel Plated Neodymium Magnet with protective metal cup Model: MR16 Our price: $0.75 See details 20 x (8.5x4.5) x 7mm N38 Nickel Plated Neodymium Magnet with protective metal cup Model: MR20 Our price: $1.50 See details 32 x (10.5x5.5) x 8mm N38 Nickel Plated Neodymium Magnet with protective metal cup Model: MR32 Our price: $3.15 See details 42 x (12x6.5) x 9mm N38 Nickel Plated Neodymium Magnet with protective metal cup Model: MR42 Our price: $5.50 See details 75 x (19 x 10.5) x 18mm N38 Nickel Plated Neodymium Magnet with protective metal cup Model: MR75 Market price: $39.00 Our price: $30.00