Today we have a solution for N-size (76 mm) core drilling. N-size is by far the most common size for surface mineral exploration drilling.
The system we have today can easily be used for B-size core drilling also. This will use the W70 hammer, same as for N-size core drilling. The exception is when the Wassara part of hole is finished, a casing string (BW or NQ) is set in the hole to get a perfect diameter (app. 60.5 mm) for the B-size core drilling.