Use A Screen Unlock Pin - Samsung Galaxy S6 User Manual

Note: To change your unlock screen pattern, from home, tap Apps
and Security > Screen lock type.

Use a Screen Unlock PIN

1. From the Screen lock type menu, tap PIN.
2. Enter a PIN, tap Continue, re-enter your PIN, and tap OK to save the setting.
 The screen lock is set

If you fail to enter the correct PIN after five attempts, you will be prompted to wait for 30
seconds before you can try again.
Settings
> Settings > Lock Screen
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