Need some help to identify these please

[fbjr]

I think these are brass, each slightly different in size and the tips are all different as well. Each is threaded on the one end. Any help is appreciated, thanks for looking.

 

[rick67]

Those look like water valve stems.

 

[Tony in SC]

Compression fittings(missing the nuts) for a gas cylinder or appliance. Tony

 

[Back-of-the-boat]

Tony nailed it.

 

[reale bill]

tailpiece for sink faucet hookup.

 

[Bruce R]

Being a welder I can tell you that they go on regulators such as oxygen or acetylene tanks, different gasses use different nozzles and nuts, ( which you are missing), to prevent accidental mixups.