Trouble with the treads in the brass fittings?

[CalTeach]

Anyone else having troubles with the brass fittings being too tight for the cyliners? :eek:

[Gabe]

They should be tight so that air pressure does not escape. They also might be tight if you use too little or too much Teflon tape.

[Andy Brockway]

The threads are tapered. They will not screw all the way down to the cylinder.