Under what circumstances would an overstay get you banned from china for 5 years?

For people who overstay their visa in China for a long time, they need to pay 500 rmb per day up to a maximum of rmb5000 penalty. Sometimes, they need also sign a letter of apology at the PSB. I have seen someone overstayed in China for 3 year, it is serious right, but also not be banned of visa to enter China again. So, overstay is not a big problem if you perform well at PSB and show your apology. This happens only for those with criminal records in China.