I once had a hard drive of some particular vintage that wasn't able to start. I did actually get it running with a hammer tap. Got the remains of data out and replaced the drive. It was nothing special, a Unix system drive with nothing that wasn't on tape, but I just had to see if I could fix a hard drive with a hammer.
I also remember one admin who would often be seen walking between computer maintenance room and workshop wing with drives and a blacksmiths hammer labelled "format".