depth gauge

British  

noun

1. a device attached to a drill bit to prevent the hole from exceeding a predetermined depth

---

Example Sentences

During the incident the main depth gauge on the submarine failed as it was diving, a defence source confirmed, but a secondary depth gauge was still working.

From BBC

With a smaller saw - with a depth gauge set to make sure the nothing else was damaged - they sliced open an armoured glass display case, seized the tiara and a matching brooch, and fled.

From BBC

Measuring sticks that dot the river at key points and provide depth gauges related to a set historical "zero" level - instead of the river bed - have dropped into negative territory.

From Reuters

Wrap a piece of tape around the bit first as a depth gauge so you don’t accidentally drill so deep that you make a hole through the front.

From Washington Post

He uses a digital depth gauge, fish finder, and underwater camera.

From Washington Times