Shabbos 17:2

One may use a hammer to open nuts on Shabbos, or an axe to cut a fig cake, or a saw to slice cheese, or a shovel to scoop up dried figs, or a winnowing fork or a pitchfork to pass things to a child, or a reed or a weaver’s rod to use as an eating utensil, or a sewing needle to remove a thorn, or an industrial needle to open a door. (In other words, tools that may not be used for their intended purposes on Shabbos still may be used for permitted activities.)

Shabbos 17:3

A reed used in the processing of olives, if it has a knot at the end, is subject to the laws of ritual impurity as a utensil; without a knot, it is not. In either event, it is permitted to handle it on Shabbos.