652. Shearing
Shabbos 9:7
If a person shears wool or hair, whether from a domestic animal or a wild animal, whether it is alive or dead, even from the skin, he is liable. The smallest amount for which one would be liable is enough to spin a thread that is twice the distance from the thumb to the forefinger when they are fully extended. This is about two-thirds the distance from the thumb to the pinky. One who tears a wing off of a bird performs a subordinate labor of shearing. If a person spins wool from a living animal, he is not liable because this is not a normal manner of shearing, of beating wool, or of spinning.
Shabbos 9:8
If a person cuts his nails, hair, mustache or beard, he performs a subordinate labor of shearing, for which he is liable. This is only the case if cuts them with a utensil; if one removes the nails or hair by hand, he is not liable. This is true of both one's own hair and nails as well as those of another person. Similarly, if a person removed a wart, whether he used a utensil or did so by hand, he is not liable, whether they were his own or another person’s. In the Temple, it is permitted to remove a wart by hand on Shabbos but not to use a utensil. If it is dry, it may even be cut off using a utensil so that the kohein could participate in the service.