J.W. Winco, Inc. now offers GN 50.5 Retaining Magnet Assemblies, Disk-Shaped, with Tapped Hole, in metric sizes.
These RoHS-compliant magnets are a shielded magnetic assembly. To ensure that the magnetic forces are not impaired, the mounting screws must be made of non-magnetic material. For magnets with d1 diameter = 40 mm, the magnet surface is exposed. For d1 diameters >/= 50 mm, the magnetic surface of the magnet is covered with a plastic cap.
The magnet housing is zinc plated steel. The magnet is Neodymium, iron, and boron NdFeB (ND type). The cover cap is technopolymer plastic (Polyamide PA). Assemblies are temperature resistant to 175°F (80°C).