Default action bar elevation

The default elevation of the action bar is 4dp. I did a little experiment by creating one custom view right below the action bar and set its elevation to 4dp. So, both were looking the same. Official documentation also mentioned 4dp standard elevation for the action bar.

1. Nav drawer: 16dp
2. App bar: 4dp
3. Card: 1dp to 8dp
4. FAB: 6dp
5. Button: 2dp to 8dp
6. Dialog: 24dp

Here App bar refers to Action bar.

Reference: Elevation

Default value is 8dp, create dimen with this value and use on whole project, I got it from sources, but the material design guidelines state the action bar elevation should be 4dp.

The standard elevation of the app bar is 4dp according to material design spec. Here is the link: https://material.io/guidelines/material-design/elevation-shadows.html#elevation-shadows-shadows