2.1.3 At what efficiency level does a worm gear become self-locking?

The self-locking effect of a worm gear depends, among other things, on the helix angle of the gear teeth, the speed, and the type and temperature of the lubricant. Self-locking increases with decreasing efficiency. A distinction is made between static self-locking (Rs) and dynamic self-locking (Rd).
There are 3 areas of self-inhibition:
A) Self-inhibition occurs when the efficiency is less than 0.45.
B) Uncertain self-inhibition if the efficiency is between 0.45 and 0.55.
C) There is no self-inhibition if the efficiency is greater than 0.55.