The main tube and stem are made of steel in all models.

Despite my best efforts, the main tube hit the work bench top harder than I had intended.

One of the drips had at least five bags feeding into the main tube.

He watched the British officer lean into a little chamber off to the side of the main tube.

On either side of the short main tube I drew longer matching cylinders.

Since the main tube tended to be too long, the general intonation was a bit flat.

Since the main tube of this instrument is square, it can be applied to any plane surface.

Three of them gave onto main tubes like the one they had just come from.

The main tubes and apparatus are warm now, ready for operation if necessary.

I've got about half power on the forward main tubes.