Give some old tennis balls new life by using them in crafts or as inexpensive casters for furniture. To cut a tennis ball, use a very sharp thin-bladed knife or cutting tool. Tennis balls are rubber balls with a fuzzy felt cover. This material frays when a serrated edge is rubbed across it, making saws poor choices for cutting and slicing the balls.
Place the tennis ball into the bench vise and tighten the vise so the ball stays in place but is not so tight that it becomes oblong.
Place the scalpel blade or sharp knife blade on the surface of the ball and push straight down to make the initial cut.
Slide the knife edge around the tennis ball to make a continuous cut and remove the tennis ball sections from the vise.