Which do I use?
It's all going to come down to what your blade condition is in. If it’s in a poor condition, start with SO stones. The SO stones are have the lower grit (150, 220, 320, 400, 600) stones, which will give you an excellent edge.
If you would like a smoother finish on the blade I would switch over to our HA line of stones and use the fine kit which contains 320, 400, 600, 800, 1000, 1200 grit stones and is an aluminum oxide stone specially formulated for stainless & surgical steels.
"SO" General Purpose Finishing Stone
General Purpose Finishing Stone · Silicon Carbide · Grey Color
The Falcon Tool “SO” finishing stone is a medium-hard structured silicon carbide stone with moderate breakdown used for general polishing on tool steel and non-ferrous materials. It is harder than our “PO” finishing stone and can be used by hand. "SO" can be used with or without a lubricant.
Available in 46-1200 grit and a wide variety of sizes including round shapes. Also available in convenient and cost effective Finishing Stone Assortment Sets.
Silicon carbide finishing stones vary from aluminum oxide finishing stones in that the particle shape of the grain is thinner and sharper than aluminum oxide particles. Silicon carbide particles shave a narrow cut in the material being polished and produce a less brilliant finish because the narrow cut does not reflect as much light. Silicon carbide tends to shape easily to contours and is typically fast cutting and breaks down quickly.
HA" Specialty Finishing Stone (Fine Grit)
Specialty Finishing Stone · Treated Aluminum Oxide · Cream Color
The Falcon Tool “HA” finishing stone is a hard-structured premium grade aluminum oxide stone that it specially treated to create a load resistant, smooth cutting action. The “HA” is the perfect stone for polishing ribs, slots, letters, and hard to reach places because of its hardness and will hold its shape making it ideal for polishing sharp corners. It is an excellent stone for polishing EDM (electrical discharge machining) surfaces and performs well on all types of tool steels. The “HA” can be used by hand. It must be used with a lubricant such as our Stoning Oil or Polishing Lubricant and Diamond Thinner to prevent stone loading.