First off DON'T use the TNT unless you believe the edge to be damaged and you want to see how much. Your thumbnail is agressive enough to damage your shaving edge. Besides it feels to me exactly like fingernails on a chalkboard sounds and I can do without that.

The TPT requires a very sensitive attention to minor changes but what I have noticed in the progression is this.

1. The edge feels sharp, like a well honed knife, ready to cut a tomato effortlessly, but this won't shave. This is what I usually feel off the 4k Norton.
2. The edge starts to refine and provide a slight tickling sensation. This would be considered 'scary sharp' for most knives. It won't quite shave well though, pulling to various degrees.
3. The blade starts to exhibit a slight gripping or biting in sensation. Just as this starts I move to the HHT. If it's right the shave can be great.
4. The overhoned edge grabs or bites in to the thumb pad very easily, but had trouble shaving comfortably. Definitely too much work on the 8k and it's time to go back to the 4k for more than just a 3/3, 1/3, 1/3.

Each blade is different and there are many shades of grey in what I've described, but that's my general sense of it.

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