These extremely powerful Roebuck magnets have the unusual feature of a countersunk hole in the centre. This makes them easy to secure in place using a countersunk screw. They are ideal for use in repulsion to create magnetic dampers or magnetic springs. They are also excellent for attracting through relatively large airgaps and securing parts which are thin, uneven and difficult to hold with other magnets. Max operating temperature 100°C. Plating - Zinc Grade - N38