Manufacturing Piston Rings | Practical Machinist

Hi everyone, I've been assigned to come up with a process to manufacture piston rings for our customer. The catch is this is completely out of our line of work. We normally do overlay coatings for oil and water pumps amongst various other things. We are used to machining those types of materials and stainless steels. I really don't even know where to start with this project. The rings go into a steam valve they are made up of two different split rings. 5.757 is the OD with a .230 wall thickness with the two rings together and a .147 gap. Outer ring is made out of Ni Resist D3 normalized. Inner ring is 17-4 PH cond. H-. Having a hard time finding any info anywhere I hope someone can give some pointers.

Thanks. As Garwood said, usually piston rings are coiled. Rings are easy to make, but an art to make round and have them actually seal. If you can, go to someone like these guys and just have them make your ring. You'll save yourself a lot of grief. Home : Pacific Piston Ring That's what I originally told them. We just need to let the professionals handle this one, but they disagree. We are slow right now so they are trying to pull in everything they can. I personally think we bit off more than we can chew with this one. Thanks for the input though. My initial, gut feeling reaction to this one is: Stay away!

Pistons and piston rings are made by a handful of very specialized companies with a gazillion years of knowledge and experience.
During all those years, they've made all the mistakes possible, found solutions and can deliver reliable parts.
If you want to go through all this trial-and-error, you'll only experience pain.

Even the big car manufacturers don't make their own pistons and rings.

Benta. Twenty years ago I toured a nearby plant that made piston rings.

From what I remember they were stacked and locked on a mandrel, probably 50 at a time. A cam actuated lathe then turned or ground them out of round. When the gap was cut out the ring was round when in the cylinder bore.

They were getting about 5 cents each and the resale was dollars each. Seemed like a very efficient operation, but was bought out a couple times, and then shut down.

Dave Piston rings look like a very simple round object. THEY ARE NOT. Piston rings are an extremely complex shape that you will not make successfully without a heavy investment in research and machinery. Piston rings are only round when they are compressed within the cylinder. They are actually a very complex shape that becomes round when compressed. I would think that trying to make piston rings to fill in for a slow time would be a very good way to go broke in a hurry