You can also fully penetrate a screw even if the rubber coating is closed at the other end

This one is measured at 10

which you cannot achieve with a permanent magnet without this kind of protection

But at the same time

Gummimagnet (hvid) m. indvendigt gevind, Ø31 mm. BF Tier1 You can also fully penetrateSmall but strong pot magnet with a rubber cap and internal steel thread (M5). The magnet itself is made of neodymium N42. The coating is made of white rubber. Diameter: 3. 1 cm. Height: 0. 6 cm. Thread: M5 Strength: approx. 8 kg. Screw this magnet on another magnet with treaded stud or use a normal screw or a M5 bolt. The internal steel thread is continuous you can screw all the way through the rubber coating eventhough the magnet is covered with