Hey guys, what do the phrases here mean:

"He worked in a toothpaste factory, where he sat all day long at a bench and screwed the little caps on to the tops of the tubes of toothpaste after the tubes had been filled. But a toothpaste cap-screwer is never paid very much money, and poor Mr Bucket, however hard he worked, and however fast he screwed on the caps, was never able to make enough to buy one half of the things that so large a family needed."?

Roald Dahl. Charlie and the Chocolate Factory (Puffin Modern Classics relaunch) (Kindle Locations 100-102). Penguin Publishing. Kindle Edition.


Here are photos of tubes of tooth paste, some with the cap screwed on and some without.https://www.google.com/search?q=photo+of+tube+of+toothpaste&client=firefox-b-d&sxsrf=ALeKk02s578OOr VoVNVe3BhYrxUUV4vMw:1595073298298&tbm=isch&source=iu&ictx=1&fir=TcHNqq5WUtB97M%252CwrwbPElR0CNB8M%252C&vet=1&usg=AI4_-kTZWkcP-JPotypWxOc470j8u9qHKw&sa=X&ved=2ahUKEwiBm9eK39bqAhVOneAKHXcPDKwQ9QEwAHoECAoQFQ&biw=1920&bih=938#imgrc=TcHNqq5WUtB97M

The grooves on the top of the tube it into the grooves on the inside of the cap. The twisting motion that you do with your hand to put the cap back on is called screwing the little cap back on.

Dahl is talking about a person who has a job screwing caps on. Dahl calls him a cap-screwer.

In reality, I think this is a job that is done by a machine. But Dahl is writing a funny story, so he has invented this job for the person in his story.