Manual Stretch's to much force?

This will probably tough to gauge/explain. How would you know if your using to much force during manual stretch routine? Pain and an injury is obvious. I’ve work with my hands my whole life, my grip is probably a little stronger than average. Example; I use as much force as I can without my grip slipping off. No pain or injuries, I have some conditioning, but starting again with the newbie routine.

The only thing I can say is that if it is painful or you start seeing lesions, then your tugging too hard. Some discomfort is fine, but never should there be pain or cuts.

Gets dangerous when we have a fully warmed and a conditioned penis because you won’t be able to feel much the stretch. Thinking everything is ready for further force, then an injury/condition happens.

Won’t be able to help much because never got too deep into the stretching world, but the outer limit is clear and it starts when we will have to apply tremendous amount of force to draw an additional milimeter in length: this extra force should be avoided, because penis already reached his limit.