I have never heard a conversation regarding the need to place a shoulder on a tenon which is to be placed in a collet as is done when using a scroll chuck. My logic tells me that there might not be a need for one for the following reasons:
- a collet provides close to 360 degree contact with the tenon, providing greater gripping ability
- the length of the tenon used in a collet can be made longer than the typical tenon placed in a scroll chuck thus making it more difficult (virtually impossible?) to unseat the blank in the collet
Does this sound rational? If you at times use a collet, do you place any kind of shoulder on the tenon? I ask this question with finial making in mind.