Can SAT Material be used for studying for the ACT?

I mainly have SAT Practice Test

No. You would waste a lot of time. Use real ACT tests.

I’d advise you to study with ACT material, so you get a feel of the questions, format etc.

The questions are much more straight-forward, so oftentimes answers that seem to easy to be true actually are the right answers.
If you study with ACT material, you can answer such a question in a few seconds and confidently move on.

It is best to use ACT tests for practice.

Here is one

http://www.act.org/aap/pdf/Preparing-for-the-ACT.pdf