This neodymium (NdFeB) strong round magnet will fit our Dia. 10 threaded ball， you'll need 12 of them for each detla magnetic joint 3d printer

N52 STRONG MAGNET SPECIFICATION
Diameter Dia.12 (mm)
Thickness 5 (mm)
Bore (Hole) 4 (mm)
Material Neodymium Magnet

Package Includes
18 x N52 Round Magnet