I know these aren't the same screws, but since we're on the subject of servo screws....
If you're interested, considering buying hex head servo screws like these from RTL Fasteners:
http://rtlfasteners.com/RC/d.html
I ordered a 100 piece bag of both 7/16 and 9/16 sizes a few years ago and I still have dozens left. It was one of the best investments I've made in this hobby...now I never have to worry about servo screws!
(Note: I do not work for the company, just thought I'd share a product I was very satisfied with [8D])