How to subtract an extruded body

I made the spiral and barrel, now i hide the spiral but i don't see the cuts in the cylinder.

I want to make a round thread with the spiral, i wanted it to remove material from the inner cylinder, but although i unchecked Merge Result in the Extrude Property Manager, i don't see the thread.

41-24-15 Drum turning.SLDPRT

You could have saved a lot of work with a simple Helix Sweep-Cut for the entire number of turns rather than copying them and then a couple of Extrude-Cuts on the ends.

For your solution - Insert>Feature>Combine - Subtract

I made as you said, one helix with 6 turns, but now the Insert>Features>Combine is greyed out

Drum 2.zip

I didn't open your file, but -

Create the cylinder first.

Then create the Helix path (you can add the straight sections to the ends of the path, but you might concentrate on getting the basic Sweep-cut first).

Then Sweep-cut the circle along the path.