SMT red glue is the thrust of the original device in the PCB board after the use of force to calculate the tensile force, the general tension is more show that the higher the viscosity of red glue, the better, the original device is not easy to fall off.
The first test: when the thrust meter with PCB is 30-45 degrees, to push from the component force band, respectively:

0603C                   1.5KGF
  0603R                   1.8KGF
  0805C/1206C           1.75KGF
  0805R/1206R             2.0KGF
  MELF                     2.0KGF
  SOT/SOPIC               3.5KGF
The second is to test the direction of thrust and PCB level, but also to push from the component force band, respectively:0402                     0.8KGF
  0603                     0.85KGF
  SOT                       1.2KGF
Third species, is the reference IPC-610C)
The minimum thrust element type of the element type
0603 1.2Kg diode 2.5Kg
0805 1.5Kg transistor 2.5Kg
1206 IC 2.5Kg 1.8Kg