How are piston rings made?

A lot of interesting comments. Most everything is just as described. I found it interesting because my wife retired from Dana. She, her dad, and 4 of her brothers all worked at various Perfect Circle plants in and around Hagerstown Indiana (Richmond is the county seat). Many considered PC the premier ring manufacturer for years. All 7 plants in that area are now closed, some stuff went to the Sealed Power plant in Michigan, some to Hasting Nebraska, but the hi pollution stuff went to Mexico.

The type 98 oil ring invented by the Teetors was a really interesting ring. It was a Cast Iron spacer, 2 steel rails and the expander spring behind. The trick was cutting the slots, my wife usually did packaging or inspections but one time when work was slow in the 70's she had to do that job (they called it groove). It was basicly an indexing lathe with a set of milling cutters that were plunged in to the rings at several locations. The rings were "potted" on an arbor with spacers, compressed and clamped down. If you screwed up and cut a slot where the gaps were it was all scrap. Sometimes it would kick a pot out if you didn't get it seated correctly, that was pretty exciting. The Teetor brothers as Perfect Circle are also responsable for teflon valve guide seals, the speed control(Speed-o-stat,before electronics were a real factor), perfecting the chrome plating process for rings and also perfecting centrifigal casting for cylinder liners.

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They used to use a lot of local vehicles for testing various piston ring and cylinder liner setups, I had a JD with test rings in it. That set ran hours and only burned a total of 7 quarts of oil (they changed it for me every 150 hours, weighing what went in and came out every time).

By the way the marks that indicated which side went up were very important. Most of the oil control rings had a slight taper grind on the face and it needed to be cone side up so on the down stroke it would scrape the oil off the cylinder wall insted of riding over it and letting it get into the combustion chamber.

Also most PC rings that were one piece were ran through "face lap", a machine that ran the rings for a number of cycles through a cylinder sleeve like machine with a fine grit compound. This is where you worked if you had low seniority. I don't know if they pioneered this process but it was responsible for eliminating the extensive break in period for new engines.

Sorry for running on, but thanks for the memories you brought back.

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