Originally Posted by AusCan
They could be a metric metric screw.
By the looks of your drawing, they appear to be a 82 degree countersunk head which is commonly found on metric screws.
The most common imperial countersunk screws have a 90 degree head but small head screws can be 60 degrees. Keep this in mind when shopping around.
Do you have a very small protractor to measure the screws?
Thanks! I'm not sure about the angle, the drawing isn't an exact representation of the actual screw, it's just a key for the dimensions. The head does appear to be 90 deg, the countersink hole does seem to neatly fit the square corner of a scale.
I did a test fit of a #10 screw, it finishes just shy of flush, probably not a bad thing for the rub rail, and with all the screws the same, would not be an aesthetic problem. I plan to fill holes with thickened epoxy, might as well do them all, then the #10 screws will fit fine. I'd likely be the only person who would notice...