Khoan cắt bê tông 101

The title is a joke.

But after digging a few holes on the wall, I think I should leave a few notes for the future me.

Be careful to choose countersink drill bit (aka mũi khoan).
- I pick wood type to drill on the wall, and ... it's broken :(
Always wear gloves to protect your hand before touch the drill bit.
- It cut my hand :(