what is the highest grade/field strength magnet in the market?

[Cairun]

i've got some n43 neo magnets, but i think i need stronger magnets.  i searched the internet for several sites that sell neo magnet, and the highest grade i've seen was about n48, with very limited shapes and sizes...  anyone knows where i can find magnets with higher grades with different shapes and sizes? preferably tube magnets.  thanks in advance for any help.

[0c]

How about some N50s?
http://www.supermagnetman.net/product_info.php?cPath=30&products_id=117
http://www.supermagnetman.net/product_info.php?cPath=30&products_id=118
http://www.supermagnetman.net/product_info.php?cPath=30&products_id=119
http://www.supermagnetman.net/product_info.php?cPath=30&products_id=121

[Honk]

The strongest available for sale is N54 but labs are working on grade N56.
Some distributors might even sell N55 but they are rare to find.
But instead uf using stronger grades just can just as well use a weaker but
thicker magnet to reach the same strength. That will be cheaper as well.

I've read that the strongest NdFeb magnet possible in theory is grade N64.
http://en.wikipedia.org/wiki/Neodymium_magnet
But I guess that we will have to wait for many years before we get there.

[Cairun]

thanks for the suggestions. 

to oc,
it's a good site.  there could be a bit of problem with the SI units though because i usually work with English units.  i appreciate your help though.

to Honk
it's true a higher field strength can be reached with a longer magnet, but i need the mass of magnet to be as small as possible.  thanks for the suggestion. 

[hazens1]

I've got a bunch of 1/4"x1/4" cube N52 magnets. They are pretty tiny, 64 in a cube that totals 1"x1" cube. Each one has 5lb pull. All together they exert alot of force. You can get pretty strong and tiny in the N52 range. I think I paid about $6 for the 64 1/4" cubes. Good site to find N50 and N52 is http://www.kjmagnetics.com/products.asp?cat=168

These tiny 1/4"x1/16" disc magnets have 4lbs pull force http://www.kjmagnetics.com/proddetail.asp?prod=D41G%2DN52 you can get 50 of them for $13.