Carbide polishing

A. All the hand stones that I know of are either aluminum oxide or silicon carbide, none of which has enough hardness to effectively polish your substrate. You'll have to use diamond in successively finer grits with suitable backings, enough pressure and SPEED. Brass, wood, wool or plastic are some examples of low cost backings. Nickel or cobalt are tougher and better. The selection will depend on shape, ease and fixturing.

A. This doesn't exactly answer your question. I have worked with and developed some processes for another carbide company that puts a mirror finish on small carbide parts. We do use small vibratory deburring mills and some exotic media. Because of the hardness of carbide, these are long time cycles and there is no problem with removing too much material.

A. I would think a process similar to the old one used for instrument jewels would work.

Basically it's just using a rolling cylindrical cradle with holes on ether end. Stainless wire close to the required diameter is passed through the cradle and the parts are strung onto it like beads on a necklace. About the distance of one part is left without parts on it.

The stainless wire is pulled back and forth with a stroke length about four to five times the length of the cradle.

The wire is rubbed with diamond paste.