These neodymium magnets, are more commonly called rare earth magnets and even though they are small, they pack quite a punch. The easiest way to separate them is to slide each one off the others and not allow them to slam together. (photos show the small size magnets)
Small = .375" in diameter by .0625" in height (pull force of 2.2lbs)
Medium = .5" in diameter by .0625" in height (pull force of 3lbs.)
Large = .5" in diameter by .125" in height (pull force of 6.6lbs)
Please take care when working with these magnets and do not allow them to slam together since they may peel, crack or shatter. Their strong magnetic fields can also possibly damage magnetic media such as credit cards, magnetic I.D. cards, cassette tapes, floppy disks, and videotapes. They can also damage televisions, VCRs, computer and CRT monitors and other electronics.
The small magnets are great to use in multiples in the same tin to give you more coverage as you try to get your tin to attached to a small nail or screw. Two to three magnet sin the slider tins will give the most advantage of making sure your tin attaches to a smaller metallic surface such as a nail top or bolt.