Summary for chrome plated piston rings Discussion
Lapping of chrome plated piston rings is discussed in the context of whether silicon carbide or aluminum oxide is the better abrasive. Sérgio Castro Pinto asked because a Portuguese piston ring factory uses SiC mixed with hydraulic oil in a cast iron sleeve, even though he expected alumina to be more suitable for chrome. James Watts replied that diamond would be best but is too expensive, and that silicon carbide is actually harder than aluminum oxide and breaks down less, so it cuts longer and better; in his view, if the process works, SiC is the cheaper practical choice. A later question from Shivam Singh about removing chrome chipping from piston rings did not receive a technical answer, only a request for more context before advice could be given.
Q. I’m a portuguese mechanical engineering student and I would like to know what’s your suggestion in relation to lapping piston rings with chrome plating. This is a subject that I have to explore for a discipline. I’ve contacted a piston ring factory here in Portugal (there are only two) and they use SiC mixed with hydraulic oil, and the rings are lapped in a cast iron sleeve. I know that SiC is very good to use in cast iron, but for chrome, I thought that alundum (Al2O3) was more indicated. I’m asking you because they confess that they use SiC for a long time and never questioned the process.
Best regards.
Sérgio Castro Pinto
Research – Porto, Portugal
2005
A. Diamond would be optimum, but that is expensive, even industrial grade. Silicon carbide is not only harder than aluminum oxide, it is stronger, i.e., it breaks down a lot less so will cut longer and better. Thus cheaper if it works and it appears to work.
James Watts
– Navarre, Florida
2005
Q. Sir, how can we remove chrome chipping from piston rings?
Shivam Singh
Student – Meerut, U.P, India
July 22, 2013
A. Hi cousin. You’ll need to take the time to post a paragraph that provides some context. Sorry, but nobody knows whether you are a hobbyist trying to sand out a nick you’ve found in a piston ring in your vintage car, or whether you are an intern looking for an automated machine to repair tens of thousands, or whether you are an operations analyst trying to figure out how to handle and package your product line so they will stop chipping. Context please!
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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July 2013