STRONG NEODYMIUM MAGNET. Each magnet can support a 5kg pull vertically from the magnetic face when in flush contact with a mild steel surface of equal thickness. PREMIUM COATING & MATERIALS. Each magnet is coated with three layers of nickel, copper and nickel to give superior corrosion resistance and provide a smooth and clean finish. CREATE A FULL CIRCLE. 90-degree curvature. Four of these are required to create a full circle. SPECIFICATIONS. 20mm O.R. x 12.5mm I.R. x 90 Degree x 5mm thick. 5kg Pull.