Dear reader I need some help on carbide polishing. I grind carbide that has shear angles on it. My problem is that I need something that I can polish by hand for taking the grinding marks out. I was thinking that I might have to make a fixture that meets the shear angles and diamond lap it, but that's time and money required. Got any solutions on certain hand stones that I can use for hand polishing carbide? Also the finish that I'm looking to obtain is a mirror finish.
Thanks for reading. Have a great day. Dave Preston
Tool and die - Brampton, Ont, Canada
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.Guillermo Marrufo
Monterrey, NL, Mexico
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.
Nova Finishing Systems Inc.