Ed is correct.
In a case like that Darren, the inclination angle of the insert varies on boring bars as (in the case of a CCGT) the 7º side clearance angle may not be enough to avoid rubbing the bottom edge of the insert within a bore. Of course tipping the insert reduces the effective top clearance angle (a.k.a. rake) of the insert's chibreaker, so many insert makers offer boring-specific insert geometry. For turning tools, the standard 7º front and side clearance angles are more than enough so inserts sit flat in the turning holders.
hth
In a case like that Darren, the inclination angle of the insert varies on boring bars as (in the case of a CCGT) the 7º side clearance angle may not be enough to avoid rubbing the bottom edge of the insert within a bore. Of course tipping the insert reduces the effective top clearance angle (a.k.a. rake) of the insert's chibreaker, so many insert makers offer boring-specific insert geometry. For turning tools, the standard 7º front and side clearance angles are more than enough so inserts sit flat in the turning holders.
hth