Stem screws

Teach

I have two allen key screws which go into the handlebar stem on my Specialzed mountain bike. They are starting to round off. I believe they are 8mm. I went to my local bike shop and whilst they had the same length and width screws, they had significantly bigger heads. The head needs to be smaller (narrower) to fit in the recess in the stem.
What is the correct name for these when I search on the internet.
Where can I get some from please.

nicklouse

take then to a Bolt shop.

Knowing what stem may help but I not much.