what's the name of this very common anti-rotation feature that prevents two surfaces from rotating?

ode_tujoy

I'm trying to sketch something that I don't even know the name of. 

Its a really common feature that you see on a lot of things; e.g a rotating part joined to a fixed part, like a phone holder or anything where you have two or more surfaces that you need to lock into place. The lock mechanism is usually a thumbscrew that passes through the two parts.

The face of the "feature" is a concentric series of V-shaped ramps (peaks and valleys) with a hole in the center by which a bolt or thumbscrew passes. Both parts when mated together lock into place by way of interlocking within each others peaks and valleys. This prevents the two faces from rotating. To adjust, you unscrew the clamping device till the "ramps" clear each other, rotate to a new position, then re-clamp allowing the ramps to re-engage, thus locking the part.

I'm sorry if I'm not describing it very well. I see it everywhere, I'm sure you have too. Its a super common anti rotation feature.
I'm having trouble sketching this feature and want to see if google can help but for starters I don't know what this type of pattern is called. 

Please forgive. I'm just a hobbyist with only two unique drawings under my belt. 

GregBrown

This is called a Hirth joint or Hirth Coupling

Evan_Reese

I've never known the name of them even though I've designed them. Thanks, Greg! In googling it I found a tutorial for it using Onshape, so that seems relevant. https://www.youtube.com/watch?v=tbBrf8WJM5o

ode_tujoy

This is great! Thank you!
Hearth Joint... I would've never in a million years figured that out. 

You all rock!