what kind of end cap is this?

[kurtyboy]

I've seen them used on 'sink tube' sabers, and even ATAT helmets...

What exactly are these things called?

 

[JoeG]

They're called hole plugs. They're usually chrome plated and used in covering up holes in sinks.

 

[kurtyboy]

Typical, that seems to be what they are called in the US, but over here in the UK that term doesn't mean much!

Thanks for the tip though... now if I can only figure out what they are called over here

They're called hole plugs. They're usually chrome plated and used in covering up holes in sinks.

 

[kurtyboy]

Thanks this helped. Found one!

 

[LeAngeSolitaire]

It looks like a tap cap, used for covering the screw fixing a tap wheel in place and also denoting hot/cold taps. The reason they are used for sabers is I suspect they were found on the Obi Wan saber handwheel knob.

 

[Organic Mechanic]

That, and they are pretty handy for closing off the end of a sink tube saber.