These springs are absolutely perfect. I bought them for my Ibanez RGIR27E, as using higher gauges, I've had to use 5 standard springs in the tremolo to get the perfect balance between spring and string tension. However, I recently upped the gauge to a 10-64 set, as for the faster death metal that I play, the increase in tension is essential. I did originally buy 5, expecting to need to use 4-5 to still achieve the right balance between tensions, however I'm only using 3 on the bridge and it's absolutely perfect.
I cannot recommend this enough. The only problem that I had was they're a little shorter than usual springs, however this really isn't a big issue.
If you want to increase bridge tension without using stupid amounts of springs, these are exactly what you need.