As this came up in the How-To-Make-a-How-To-Thread, I have given it a try:
Here are some useful threads if you are looking for information on caged or captive nuts. All found by searching for "caged nuts" using the search function on this site, grouped here - in no particular order - for your reference:
Caged nuts for Stuart tank
cage nuts
Caged nuts for CMP's
Availability of new Captive Nuts
Source for Cage Nuts used on CMP
making new cages
If you find anything useful on this site, please add it here.
HTH,
Hanno