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Grinding Surface Finishing

I have a problem in achieving grinding finishing on the chrome-plated surface. The work piece is like one end-blocked cylinder, the grinding surface is 4.73" in external dia. and 25" in length chrome-plated. Its internal dia. is 4.422" so wall thickness is .156". We use cylindraulic grinder to grind. The part is located between one end in internal diameter chamfer and centre hole made at the blocked end. The surface finishing our customer requested is between Ra 12 to 18 microinch without grinding defect (such as feed line, barber pole etc.). Currently we can only achieve surface finishing is Ra10-12 even less than 10. I seek recommendation on what is the best type of grinding wheel, grinding parameter and coolant should be used.

Thanks in advance for your kind response.

Zhou JH
Machine Shop - Singapore
2004

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If you have a lot of volume, you may want to consider an alternative process such as an abrasive extrudehone system. It is an expensive piece of equipment, but you can't beat its ability to work I.D. surfaces.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2004

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2004

Dear Mr. Kenton,

Thank you for your reply. What I am going to grind is O.D. chrome-plated surface. I want to get the surface finishing ONLY within the range of Ra 12-18 microinch. The volume is about 8-10 pieces per month (quite small). Do you think the abrasive extrudehone system you mentioned suitable for it? Could you please give me an outline of the system and what kind of abrasive should be used. Any other alternative process could be used, please advise.

Thanks again.

Zhou JH
- Singapore

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After seeing you reply and getting a little more info, I say NO do not consider the Abrasive extrude hone system. I originally thought you needed to work the ID. From latest info, you should look into a system called drag or spin finishing. This is considered a mass finishing system in name only. Basically the parts are fixed and can rotate as the media moves or spins around the parts. In some system variations the parts spin faster than the media.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2004

Our company does some similar type grinding except it is on OD journals. Do you have any recommendations on type of wheel, speeds, and feeds. Currently we are using a grinding wheel, RAA-601-K6-V8, with a wheel speed of 1,500 rpm approx.(max. speed of the grinder), wheelhead speed of 30rpm, and in feed of 0.00002. We would like to process the parts faster. Does anybody have any other recommendations? Thanks.

Chris Barnes
- Tinker AFB, Oklahoma
2004