6. Little Hole In A Padlock
When you check the bottom of your padlock, you will notice there is a little hole close to where you put the key to unlocking the padlock. This might mean nothing to you but it is there for a purpose. The hole is meant for you to grease your padlock in case it gets rusty and gets stuck and you need to get oil in it. It is also meant to drain water that gets trapped in the padlock. If your padlock does not have the hole, then it is made out of stainless steel and it is supposed to be used indoors to prevent water from getting in.