Originally Posted by Docfxit
This house was built 7 years ago. I don't understand why they would put metal across the header.
As you state you are drilling down through two of these "headers", I'm guessing you mean the top plates of the wall. Depending on where the hole is and whether the wall is load-bearing or not, there is a pretty good chance you've run into a structural strap, similar to an MST or LST:
If so, the answer isn't how to drill through it but rather, where to move your holes to.