iOS Security Guide [apple.com], Seite 15:

To further discourage brute-force passcode attacks, there are escalating time
delays after the entry of an invalid passcode at the Lock screen. If Settings >
Touch ID & Passcode > Erase Data is turned on, the device will automatically
wipe after 10 consecutive incorrect attempts to enter the passcode. […]

Delays between passcode attempts
Attempts Delay Enforced
1–4 none
5 1 minute
6 5 minutes
7–8 15 minutes
9 1 hour