the company i work for will take 1/2 hour from your pay if you work over 6.5 hours. we have to clock out for lunch, they allow 1/2 hour for lunch. my question is, under ohio, federal law, can they take 30 minuets from my pay if i decide i dont want to go to lunch?

No. But if they want you to take a lunch and you do not do so, they can discipline you in any other way they choose to, up to and including termination.

The bottom line is that if your employer wants you to take a lunch, you take a lunch. It is THEIR choice, not yours.