The Hyundai DURAWING 165 is a Concentric Overburden System designed for casing of 215 mm diameter holes through varying formations into bed rock.
The wing bits are enclosed making them the most professional & efficient system on the market today as they are not exposed to "clogging" in loose overburden material while drilling down to the bedrock.
When the drilling starts, the bit wings protude utilising a unique cam sliding mechanism. The key feature of the DURAWING 165 is the self actuating wing bit system that works perfectly everytime.
 
Drilled Hole Diameter: 215mm
Casing Size O/D: 205mm
I/D: 178.8mm 
 
Major Body Diameter: 178mm
Length: 
System Open: 215mm
Casing Size: 178.8 / 205mm
Total Weight (approx): 
Hammer Type: QL60, DHD360, SD6, M60