OKA-233 Okamoto Straight and Profile Grain Dressing Plate

Straight and profile dressing large hard wide wheels.
10 mm depth x 20 mm wide hand set Grains.
W Tungsten hot-pressed bond. Center mounted plate is set into
5mm x 22mm x 13mm blade is set at 0 degree angle
12mm diameter x 20mm long with 120 degree mounting grove.
Suggestions for Wheel grit size.
Part Code, Wheel grit size
OKA-233 30/40
OKA-232 50/60