Best magnets to use for magnetizing bases

[hd3]

I've been having trouble finding a strong and consistent brand of magnet to use to magnetize my bases. My warp talons still drift a little even though I've out multiple magnets in each. I was wondering if anyone could suggest a good size of magnet for holding my bases in place?

 

I'm mainly using them 25, 32, 40, and a single 51 mm base. But I also have four 60mm and one 80mm base to magnetize too.

[derLumpi]

I use 5x2 round ones. But you have to be aware that there are differences in the power they have (don't know the correct english term). They have ratings like N52 and the higher the number the stronger they are. So I use 5x2 N52 which is enough for 32mm and two of them are enough for Contemptor size models. 

[jaxom]

I use 5 mm x 2 mm N35 on magnetic sheeting material.

[Heraclite]

I use 6mm x 2 mm, no idea of their rating, in metal "biscuit" boxes. For infantry models one is more than enough. I use 2 for oval bases, and 4 for my redemptor and ballistus dreads and 6 for my repulsor

[MARK0SIAN]

It depends a bit on what I’m sticking them to. If they’re going to go on a metal shelf then I’ve found that the stronger ones tend to adhere a bit too well and end up being pulled off the base when you lift the model up. If you’re using the sheets you can generally get away with it a bit easier.

[Ming the Merciless]

I've been using the sticky magnetic sheets and plastic boxes with 5x2 n48 (one per base up to 40mm) and have had no issues so far (even with models upside down).