Hole reducing bush/washer thingy

[Barlidge]

Despite googling with various terms I'm struggling somewhat to find some hole reducing thingies like the ones pictured below, I'd like to reduce some holes from M16 to M8 and they would need to be stainless. Any pointers greatly appreciated.

 

[Hitch]

A 'Flanged bush' I would call that....if it was a bush, not a spacer...might be a start...

 

[vladrat]

top hat spacers i think they called,maybe?

 

[Barlidge]

Thanks for that, I'm getting some hits on that but not the size I'm looking for although those hits came up in Nylon/Acetal which I hadn't thought of using, so I think I might order a Acetal rod and have a little go at turning them myself.