Unfortunately, there is really not grit rating on ceramics per se.
I think that the ratings on the WEPS ceramics are sort of an approximation.
I believe the manufacturers usually rate the ceramics using a surface roughness scale, not a grit rating.
This is a quote from Sal at Spyderco (I believe that they source their ceramics from coorstec, the same place the microfine WEPS ceramics come from)
“I would be curious as to where you got your numbers for the ceramic stones. All of the ceramics use the same micron size (15-25). the different grits are created by different carriers, different firing techniques and diamond surface grinding.
sal ”
http://www.spyderco.com/forums/showthread.php?31188-Ceramic-benchstones-compared-to-DMT-extra-fine
Post number 7. Read the whole thread.. it is interesting.
As to filling the gap, sort of. Many here say to use the 1.4 micron rated microfine, then the two super fine stones, then the .6 micron rated microfine. Some, Clay for one (I think) mentioned lapping the 1.4 to make it behave on steel closer to its rating. Do a search, I am sure you can find the thread.
The above is the way I have been using them. It seems to work well.
In any case, any grit rating is merely a reference number. What is far more important is what the abrasive does at the edge.
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