The shears consist of two blades which are hinged together about a pivot in the from of a rivet or screw (13). A ring magnet, which is mounted in each blade, surrounds the pivot screw or rivet. The magnets are mounted so that they repel one another. One of the magnets can be mounted on a screw plug so that the distance of this magnet from the opposing magnet can be adjusted. The plug is secured in position by a locknut.
