Generally padlocked keyhole next to a small hole, very small, only the general needle diameter, what is the use of it?
Small hole is mainly to prevent the time when the lock, lock lock lock ring will produce air closed, affecting the lock ring lock and pop.
Leaving the hole in order to put oil inside, because there is a spring and lock the beam for a long time easy to rust, so when the lock to stay so a hole, in order to clean up
1, when the lock is locked when the lock body will have a gas compression process, the hole is used to exhaust.
2, you can determine the direction of the key to enter. There is a small gap on the key, with a small gap at the hole can easily open the door lock.
