Surfacing Grinding Stones Choices/What types to use

I'm new to surface grinding. I think what I understand as for what types of stones to have on hand are 46 grit H, I, and J for most general/universal use.

I think I understand that:
H is for hardened steels, would this be something like HSS such as HSS cutters?
I is for softer steels, would this be for mild steels such as 10XX series steels?
J is for, not sure???

What type of wheel would you use for cast iron, non-hardened and for hardened???

Also, of the wheels, you have a selection of different colors/types of stone such as White Alum Oxide, Pink Alum Oxide, AZ, 32A Alum Oxide, Cermic Grain, and probably some more that I don't know about. The white and the 32A may be the same, but I am not sure.

What is the best color/type of stone for universal grinding on mild steel, hardened steel such as HSS, and cast iron? Maybe there is no such thing as a universal for all these different ones

What would you use for grinding carbide?

What about stainless steels?

What about something like D2 tool steels for forging dies?

What would you use for grinding say 4340 or 5140 steels?

When would you use 60, 80, 100, or 120 grit stones?

Thanks,
Roger

it depends somewhat on the model grinder you have. Generally finer grits yield the lower RMS finishes at the expense of higher heat and lower material removal per pass. For a general purpose " leave it on and grind anything that stick to the chuck from 1018 to CPM M4" wheel I use a Radiac 8BP46 H800 VOS. Its one of the better all around I have found, but I run 14 x 1.5 x 5 wheels on a Gallmeyer and Livingston 12 x 24.

for soft steel ( not heat treated) Norton 32A46-H grey
heat treated to 56RC 32A60- I or J grey
over 56RC we use CBN wheels for flat grinding, 32A60 or 80 K for forms
Carbide = diamond
D-2 or powdered metal, CBN or Norton SG blue

I would guess that Norton and other abrasive companies have booklets giving the info you need.

Charts available ....give brakedown.

On each digit of the "wheel" number.
Psssst don't call them stones (accept for a blanchard grinder)

Carl Darnell said:

I would guess that Norton and other abrasive companies have booklets giving the info you need.

Click to expand...

That letter in the middle is all-important.
It determines the brakedown of a given wheel.
In general harder metals need a wheel that will "brakedown"
more readilly, than say mild-steels.

D2 is one of the fussyest (in the hardened state),
Norton makes a great D2 specific wheel Blue.
But even then you just want a sort-a spray (a hint or suggestion)
of coolant, or you will have an awefull go of it.

m1m