Ring Magnets are magnets that are round in shape with a hole.
The size of a ring is given by specifying the Outer Diameter x Inner Diameter 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. Ring magnets are a good choice when you want to bolt or screw the magnet in place.

Features:
Material: Sintered NdFeB/neodymium magnet
Dimension range:
Length: 3 to 50mm
Out diameter: 5 to 200mm
Surface treatment: Ni, Ni + Cu + Ni, Zn, epoxy, gold, tin and CR3 + Zn, etc.
Applications of neodymium magnets:
Servomotor, step motor, DC motor and linear motor
Loudspeaker, headphone, earphone and microphones
Holding system equipment
Medical facility
Sound device
Wind power
VCM, MRI
Mobile accessory

Applications of Neodymium Magnets
Magnetic separators
Microphone assemblies
Servo motors
DC motors (automotive starters) and other motors
Computer rigid disc drives
Magnetic resonance imaging
Various holders
Toys
Meters
Odometer
Sensors