Ring bit

Ring bit is a part of Ultra Maxbit(UMB), which has carbide buttons.

This part is used to hit and break rocks.

UMB is used for simultaneous drilling and casing in unstable ground formations. 

The dual bit system also allows vertical, horizontal, and even inclined drilling. UMB is also applicable 

for a wide range of ground conditions such as sand, gravel and boulders, and rock.