Here is the abrasive chart I stumbled on over at SRP . Later losing it and was found again by a fellow B&B shaver .
This will explain why I'm I'm getting such a clean comfortable shave with the Spyderco 306UF .
Notice the Norton 4/8K stones converts to only 1,100 ANSI (USA) grit at the Norton 4k level . The Norton 8K converts to 1,500 ANSI (USA) grit . Explaining why the Spyderco 306UF gives a much sharper cleaner edge . The Spyderco 306UF is rated at 2,000 ANSI (USA) grit per Spyderco .
The Shapton 16K only compares at say 2,100 or 2,200 ANSI (USA) grit . Possibly equivalent to the Spyderco 306UF .
Seems like all the stone slash sharpener makers use their own "grit" scale . Only comparison standard we can follow is the micron standard .
So using the micron standard we see this :
Spyderco 306UF at 1 micron
Norton 4K at 6 microns
Norton 8K at 3 microns
Shapton 16K at 0.92 micron
Shapton 30K at 0.49 micron
Smokintbird at SRP complied this