Best process

Hi everyone. I am looking to have a part made similar to the one pictured below out of 6061. Its rough dimensions are 25mm in diameter by 12mm in depth. Our yearly need is only 2000-4000 parts. My original thought was to have it turned, but this would require a secondary turning process to shape the other side. This adds substantially to the cost. It can’t be die formed from a tube either because the walls are non-uniform.

Would investment casting be a good option for 2-4K parts per year? What kind of price per part could I expect with this process?

Is there a way to mill/turn this as a single process that my machine shop is missing?

Thanks in advance for all the help.

How about forming a tube over a 2-part die.

I feel like it’s always difficult to ask for help without being able to disclose all the relevant info as is usually the case, but the more info you can share the better.

Is there any apetite to tool up? - very small tool, but 4 piece with 2 actions minimum to get your form it’s not super simple either. Then you probably want to clean up the witness lines.

Does it absolutely have to be solid 6061? - what’s the driver for that / application?
Any finish constraints?

Investment casting would work, but there would be clean-up to the cast parts and maybe inconsistent surface quality.

I was just reading about ‘centrifugal casting’ of 6061 - to create round components. Pretty cool, not sure if it applies.

Investment casting will be way more expensive than turning- you’ll need tooling for the wax, and clean up after casting. I think lathe is going to be hard to beat, even with a secondary operation. The only thing I can think of is doing the back side on a mill- then you can load up a bunch at a time, rather than doing them one by one on a lathe.

Sorry for the delay in response, and thanks for all the suggestions/ information. We priced out casting the parts. They came out substantially more expensive than we can machine them for.

Here is the process we will be likely using:

At the turning center

  • A hole will be bored slightly undersized through the material
  • The exposed face and outside diameter will be profiled
  • The part will be cuttoff

At the mill

  • The part will be placed in a fixture with the remaining side up
  • A corner rounding end mill will be used to profile the remaining side

If we can’t find an existing tool that will work, we will likely have one made.

As production ramps up, we might switch the mill process out to a purposefully built machine. Basically a CNC drill press.


Cheers indeed Soak.

Thanks for sharing the outcome of your project with us.

From a turning perspective, see if you can find a workshop that has a twin spindle lathe, this will remove the secondary process of milling because the 2nd spindle can reach out, grab the work-piece, part off, return and then the turret can perform machining on the back side.

It does increase the cycle time a lot but for those numbers it could be more competitive.

berat001, I hope your suggestion is considered, because I believe I had a client go from lathe-mill to a twin spindle lathe and saw a slight reduction in overall cost. They didn’t comment on cycle time though.