shower head 1950's

Trying to install a new shower head. The old shower arm coming from wall is not a regular arm that has threads on it. The end of the arm has a round ball ,with a threaded cap.The cap comes down to the ball then the shower head is attached with the head going over the ball then secured by the threaed cap. Need to put an updated shower head on but cant find one that will fit this type of shower arm. Do I need to remove old shower arm and intsall a new one. Have no access to see how the parts are installed inside the wall.

The threads in the wall will be standard.
Just pick up a standard shower arm at the hardware store.

I find it's easier to put the head on the shower arm first, and then thread it into the wall.
It gives you a little more to hang onto while tightening.

There are ball-end adapters which convert your arm to regular threads. There are at least two different threads....American Standard, and Price Pfister each used ball ends, and used different threads.


These are getting a little hard to find, because there are so few of them left. It might just be easier to replace the whole arm, as mentioned.

adapter

The adapter you are looking for makes the joints so manipulative that it is hard to get them tight enough to hold the shower head where you want it. Replace the arm going into the wall.