L/D is a ratio to analyze the shape of a magnet, and it is a very important parameter to judge the temperature resistance ability of the magnet basically.
Normally, we advise L/D ratio＞0.5 (≥0.7 will be even better )
L/D ratio was calculated as follow:
（1） e g, D10*6 disc magnet, magnetized direction is 6, its L/D ratio： 6/10 = 0.6, it has a good L/D ratio, it would stand the high temperature as we designed.
（2） e g, 15*15*3 block magnet, magnetized direction is 3, its L/D ratio: 3 /（2* = 3 / 16.92 = 0.17, L/D ratio is very low，so it would not stand the high temperature as we designed, we have to revise something to improve it.
For more details, please consult our professional engineers.
