It is often wrongly assumed that the lip on the top of a Morse taper recording is used as a carrier. However, the lip is only intended for easy removal of the drill from the holder. The drill is tapped out of the holder  by means of a special expulsion key ( M152 ).

Damage or twisting of this lip is usually caused by a Morse taper that is not properly engaged in the chuck, causing the drill to slip. A loose drill bit is in turn caused by damage to the Morse taper itself. This damage can be on the drill as well as in the spindle and is not always immediately visible. The damage causes the drill to have insufficient grip. As a result, the power of the drive is not transmitted via the cone, but via the expulsion lip. This will cause it to become twisted or broken. 

The solution is obvious: a damaged drill bit must be replaced immediately. Otherwise there is a risk that it will cause further damage to the spindle, resulting in possible machine breakdown.

To prevent such problems, it is recommended to ensure that both the drill and the spindle are clean and free of grease. This is to ensure optimal recording. ??Read all about the different Morse taper drills in the Dormer Pramet range here.