Hi,
I checked the Scibuddies materials tab for this project and they recommended magnets #D901, D91 and D92. I went to the company website (
https://www.kjmagnetics.com/proddetail.asp?prod=D901) and D901 is 729 Gauss. D91 (
http://www.kjmagnetics.com/proddetail.asp?prod=d91-n52) is 6500 Gauss. D92 (
https://www.kjmagnetics.com/proddetail.asp?prod=D92) is 2681 Gauss.
If you go to this link,
https://www.kjmagnetics.com/products.asp?cat=1, you can see all the choices for neodymium magnets. There's also a glossary that defines the terms used in the description of the magnets:
https://www.kjmagnetics.com/glossary.asp
Be sure you pay attention to the cautions about using these magnets. I HAVE been pinched by neodymium magnets and it hurts!
Safety Notes on Neodymium Magnets (K&J Magnetics, 2006).
"The neodymium magnets [used in this project] are extremely strong, and must be handled with care to avoid personal injury and damage to the magnets. Fingers and other body parts can get severely pinched between two attracting magnets. Neodymium magnets are brittle, and can peel, crack or shatter if allowed to slam together. Eye protection should be worn when handling these magnets, because shattering magnets can launch pieces at great speeds.
"The strong magnetic fields of neodymium magnets can also damage magnetic media such as floppy disks, credit cards, magnetic I.D. cards, cassette tapes, video tapes or other such devices. They can also damage televisions, VCRs, computer monitors and other CRT displays. Never place neodymium magnets near electronic appliances.
"Children should not be allowed to handle neodymium magnets as they can be dangerous. Small magnets pose a choking hazard and should never be swallowed or inserted into any part of the body.
"Never allow neodymium magnets near a person with a pacemaker or similar medical aid. The strong magnetic fields of the magnet can affect the operation of such devices.
If you have more questions, let us know.
Good luck!
Sybee