Where the
world gathers for metal finishing
Q&As since 1989


-----

Mirror finish on stainless steel small dia. shafts

We are using stainless steel shafts 304 and 316 grade with dia between 1.0 and 1.5 mm and lengths up to 60mm. We are currently finishing the mill finish shafts in a rather primitive manner by first treating them in HF and subsequent tumbling in a Hexagonal barrel using ceramic media charms, leather and saw dust.(Dry tumbling)

We are not satisfied with the results and would like to achieve No.8 Finish with bright and smooth surface. Can anyone guide us the correct method to achieve the desired results? We have absolutely no knowledge about selection of media ,its specifications, proper quantity etc.that will achieve these results. This is a price sensitive component and only mass production techniques can be of help as we process about 30000 shafts everyday.

Pranav Goel
electronics mfgr - NOIDA, U.P, India
2004

---

There are a couple of ways to go. Your parts are really small; therefore, the first thing I would try is to tumble with your existing equipment just part on part. No media at all. This solves a couple of problems. It should work. If you are unhappy with results, I suggest trying a treated dry organic media.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2004

---

2004

try electropolishing ref handbook-never tried-there is a lot of electropolishing solutions ,i can suggest some though I never tried any

1-10%NH₄NO₃+90%H₂O/ANODIC 5AMP/SQ.DM/T=20C/1-3 MINUTES.

2-20%H₂SO₄+60%H₃PO₄+20%H₂O/ANODIC 10-20 AMP/SQ.DM/T=60-80 °C 1-3 MINUTES

GOOD LUCK

Khair Shishani
aircraft maintenance - Al Ain, UAE

Please specify the processes carried out on the materials from raw materials to final stages to enable us to suggest the proper methods of achieving the desired finish on parts.

MR.AMRISH BOSMIYA
- GUJARAT, India
2004

---

Hello Mr.Prnav Goel,

We are presently doing some of component for our customer by using the Centrifugal Polishing Machine/system. Also the use of the correct media along with the right chemical with compound plays an important part for achieving the results.through somewhat finish can be achieved through Vibrator Bowl , but the process time is very high , seeing your production quantity it is advisable for you go for Centrifugal Polishing. Any further query is welcome.

Regards,

Rajesh Seth
- Kolkata, India
2004