It'll be fine as long as its not penetrated the casing. The tread it’s self can be swiss cheesed and sometimes is on snow tyres as you fire stud into them.
A bit of spit on your finger over the screw head and look for bubbles. If there is none then unscrew the screw, check again for bubbles. If you get bubbles screw it back in and go see the tyre fitter.
The casing its self is the pressure vessel as such so don't worry about it warming up an popping.
I've seen truck tyres shed the whole of the tread off the rest of the tyre and in the good old days of remoulds was a common thing as the donor casing is stripped of its tread right back so you can see the wires and then retreaded.
http://forum.a8parts.co.uk/attachmen...1&d=1459926556