What are these known as?

[Don]

See picture. Need to get some but unsure what I'm looking for as one of these nuts is pretty much screwed and need a replacement or several for consistency.

picture courtesy of a guide...not my pic, but that is the bolt/nut. Thanks in advance.

 

[Knuckles]

Captive tapered washer/spacer nut?

I don't know why but I feel @Jaff. would know the answer to this.

 

[Jaff.]

They'd be a flanged nut but as they're domed I'm going for

Domed flange nut...

I have no idea if I'm right lol

Edit: not domed. Lol

 

[Jaff.]

They're Renault seat nuts anyway. Get some from Renault, they weren't too expensive iirc

 

[1812lsd]

Still fitting your seat's Don?

 

[Knuckles]

I am good.

 

[Don]

Still fitting your seat's Don?

Yeah mate. Turned out subframe I got was wrong side. Just need the nuts to sort it a out.