The magnet can be held by a series of pins on the mold that surround it, pinching it in place during the injection process.

When the part is demolded from the plastic, these pins leave holes in the plastic.

A pin on the mold is inserted to a matching hole in the magnet. Pin holes are usually 2 – 6 mm in diameter, depending on the magnet size.

When the part is demolded, the pin is removed, leaving a hole in the magnet.