Help finding correct part...

I'm looking for a specific type of nut for a project. It's a brass acorn nut, sometimes also referred to as a cap or dome nut. I've been able to find a wide variety of nuts but none with the specific details I'm looking for.

The "dome" portion of the nut needs to have ribbing or fluting. I've even looked for lamp finials but that produced little help.

Here's a picture of a basic acorn nut.



Google "acorn nut" and brass to see more examples. As for the detail I'm looking for is fluting on the dome section. Looking down on the nut the fluting would radiate out from the center like the hands of a clock... does that make sense?

Fluting that looks kind of like the crimping on a .22 blank round? I know what you're talking about, but danged if I can remember where I've seen them used...

Come to think of it, I believe the ones I remember seeing weren't 100% brass, but maybe a Delrin or Nylon nut with a thin, brass plate covering that may have been "fluted" (as it were) to allow for the material underneath to expand with pressure from the bolt?