I have measured screws before and for whatever reason what I measured turned out to be the wrong size several times. Now I'm gun shy about it and usually defer to what info I can find online. This time it didn't work.
You need to remedy this. This is part of mechanics 101, week 2, day 3. First thing final bell 9AM. Buy yourself a caliper. Buy yourself a 01" "mike." They are not expensive with all the Chineseoatiized junk available. Also, various fastener shops have plastic "go no go" gauges to fit bolts into and figure out what they are. And you need a thread gauge. I'm 72, I owned my first dial caliper (Sears) in 1970. Lately, I've bought SEVERAL vernier calipers. These are all Sears/ Craftsman, made in Germany, "old stuff' bought used on Egag. There are no gears to strip, and no batteries. I have to use a magnifier to see them.
Bolt and nuts stores use these types of things. This was a very quick search, just for an example
