Educate me, I looked in the grainger cat. at the Norton AO sticks and the Norton site. There are 2 grits (220 & 150) and two different grades (H & I). What are the two different grades??
Also, the Grainger site says these are for dressing vitrified wheels while the Norton site says they're good for CBN and also work well on diamond. I guess I'd believe the Norton site write up before the Grainger.
Another tid bit -- a note said that one should use a grit 2 sizes finer than the wheel you're dressing. Since we're talking 80 and 60 grit (depending on where you buy them) then the 150 grit stick should suffice (38A150IVBE or HVBE??).
Prices have changed on the Grainger site -- 38a220hvbe 10.34, 38a150ivbe 9.73, 38a150hvbe 10.34. There's also a note on the 38a150hvbe for $4.75 but looks like quantity of 50. Didn't research the shipping.