Question:
Is a magnet mutur on shabbos or is a cli shmilachto liussur or is it machmas goofo
Answer:
It depends on the usual use of the magnet. For example, a magnet that is used to attach papers to something is considered a kli shemilachto l’heter, and may be moved for any reason. Most magnets would fall into this category. However a magnet used to hold stick pins together, would be considered a kli shemilachto lissur.
Best wishes
Sources:
ס' טלטולי שבת עמ' 32, וע'ג"כ בס' שלמי יהודה פי"א – י"ג.
