This list is made from personal experience and of course, it is subject to the mood and technique of the person applying the discipline:
Rubber spatula: Pain factor 1-2. Feels like: very short term tingling sensation
Thin wooden paddle:Pain factor 2-3. Feels like: very sharp superficial sting
Rubber/latex flogger with thin strands: Pain factor 2-3. Feels likeull superficial sting, followed by slow building heat sensation.
Suede flogger: Pain factor 3-4. Feels like: Slow-building heat sensation. If well applied it is almost like a massage. Very nice!
Leather flogger made of hard straps:Pain factor 4-5. Feels like: Cutting sensation, fast heating sensation. Can cause moderate swelling.
Wide and thick wooden paddle: Pain factor 4-5 Feels like Sharp sting with slow building internal bruising that is painful long after discipline has been applied.
Leather flogger made of thick braids: Pain factor 5-6. Feels like: Sharp cutting sensation, fast heating sensation. Will cause severe swelling. If applied on already swollen skin it will make small cuts.
Short single-tail leather whip: Pain factor 6-7. Feels like:Cutting sensation, severe superficial pain and deep bruises and welts. When several strokes overlap it may cut the skin.
Rubber-coated wire whip: Pain factor 7-8. Feels like: Severe internal pain and deep bruises and welts. When strokes overlap it may cut the skin.
Leather bullwhip: Pain factor: 7-8. Feels like: Burning sensation followed by severe pain, bruising and welting. Will cut the skin very easily.
Fiberglass cane: Pain factor 8-9. Feels like: momentary lack of feeling followed by severe pain, fast-building heat, bruising and welting. Very painful.
Rattan cane: Pain factor 8-9. Feels like: momentary lack of feeling followed by extreme pain, fast-building heat, bruising and welting. If strokes are repeated on the same spot, it cuts the skin quite easily. Severely painful.
Birch switch wrapped in copper wire: Pain factor 9-10. Feels like: momentary lack of feeling followed by blinding pain, fast-building heat, bruising, welting and cutting. It breaks the skin quite easily. Be careful not to overlap strokes. Extreme pain warning.