The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Flat mirror finish

We can't find a reliable low-cost method to get a mirror finish on one flat side of a 2" tungsten (very hard) washer. We need a finish that looks like a household mirror. We can nickel plate first since nickel should be easier to work with. We've heard claims that tumbling could work but we are not convinced. We need to know the sequence of steps to achieve the finish we need. Thanks.

Jim Lewis
- Midland Park, New Jersey

---

The important word in your question was flat. Mass finishing systems will eventually achieve a mirror finish, but it will be a multistep operation and very time consuming. If you are considering this type of processing method, use high energy equipment systems. Vibratory and tumbling will take days or weeks. Even high energy system will take hours and may not insure or achieve flatness.

AF Kenton
retired business owner - Hatboro, Pennsylvania

---

Jim:

Do you mean metallic tungsten or tungsten carbide? There is a lot of difference in hardness. For your polishing needs, it will also depend on volume. It-s not the same to polish one or a dozen parts than thousands. For short runs, and metallic W, moldmaker stones and diamond polishing compounds can do, but for large runs and W carbides you need a rigid and flat grinding mach. equipped with diamond stone and then a lapping table fed with diamond slurry in various steps every time finer down to 4 microns or probably 1-2 micron depending on "mirror" definition.

Guillermo Marrufo
Monterrey, NL, Mexico

---

 

Hi Jim,

What you are describing can be done in Centrifugal barrel finishing machines. The question is what how many parts are you talking about daily weekly or yearly. Mirror finishes are not all that difficult and the do not generally take hours and hours. Most often on medical components you can get a perfect mirror in three hours.

I hope this will be helpful.

Ron

Ron Benton
Delano, MN. USA