What is the maximum size of the magnet? How small is the minimum?

Answer

It depends on the material. The common ferrite magnets and NdFeB magnets are described as follows:
Ferrite magnet

• Round: maximum 156mm (diameter), minimum d2.5mm (diameter)
• Square: maximum 152 x 101 x 25.4mm (L x W x H), minimum L2 x W2 x 0.8mm (L x W x H)
• Ring: maximum 300 x 170 x 25mm (OD x ID x height), minimum 5.55 x 2.4 x 4.2mm (OD x ID x height)

Neodymium iron boron magnet

• Round: maximum 200 mm (diameter), minimum 1 mm (diameter)
• Square: Max 200 x 150 x 25mm (L x W x H), min 1 x 1 x 1mm (L x W x H)
• Ring: Max 250 x 20 x 30mm (OD x ID x height), min 3 x 1 x 1mm (OD x ID x height)
• The maximum or minimum volume can be made according to the actual situation. Ex: is there embryo stock for the maximum volume? The minimum volume should be limited by MOQ, etc