A cover for magnetizing a shaft of a tissue-penetrating medical device is disclosed including a sleeve member having a hollow body to form a protective closure over the shaft of the tissue-penetrating medical device. The open end of the hollow body provides a receiving space for receiving the shaft of the tissue-penetrating medical device. A magnet is disposed on the sleeve member. Medical devices and methods of magnetizing the shaft of a tissue-penetrating medical device using the cover are also disclosed.
