Gary, it sounds like you are looking for a M8-1.25 x (length)mm, Metric Cap Screws, Hex Socket Drive, Flat Head, (you don’t mention length needed.) What are you using it for? M8-1.25 is so close to a standard 5/16 – 24 thread that often you can just re-tap to the Imperial thread and loose little if any thread strength.
"I am enclosing two tickets to the first night of my new play; bring a
friend...if you have one."
--George Bernard Shaw to Winston Churchill
"Cannot possibly attend first night, will attend second..if there is
--Winston Churchill, in response