the collet will probably slip pecking or straight tapping
your best bet is to ditch the collet holder and make a sleeve to fit the tap into a sidelock ,other than that i cant see any reason you can't tap 2" deep if its spiral flute , ive done it many times with near the same or larger dia taps to more depth , chances of breaking the tap is slim to non if it is of any quality ,
if your tapping multiple holes then i would suggest monitoring the tap in between holes and watch that your not building a bird nest around the tap because it will do damage
__________________
A poet knows no boundary yet he is bound to the boundaries of ones own mind !! http://cnctoybox.org |