Thanks guys. Now all we have to do is figure out how to get them out of the computers, but I think we can manage that.
Good suggestions here. Also, if you can do a complete reformat of the hard drive before you disassemble it (reformatting it twice is even better), that is preferable.
Agreed, but bending the platters makes it almost impossible to read the data..
I bent all the ones I wanted to discard..
Make it a learning experience for your grandkids to learn how they work next time they come to visit. Hand them the toolbox and the hard drives and let them to explore the inner workings of a disk drive by tearing it apart. When they're done, proceed with all the other suggestions offered above.