Fixture mounting hardware

[Bill Briscoe]

So we buy some new outside carriage lamps to replace the old ones outside the garage. There was a mounting bracket attached to the electrical box which used 1 in screws to attach the fixture. Both the existing and new mounting brackets used the same sized screws, which weren't quite long enough to attach the fixture because of the depth of the box in the bricks. So its off to HD to get 1 1/4 inch screws. These screws seem to be the size used with every 4 in metal electric box in the nation, but aren't really the same at HD's #8-32s pan heads. They are slightly smaller, but certainly bigger than #6-32s. I bought the #8-32s at HD and forced them info the threads on the bracket, but my question is: Are there different sizes/types of #8-32s out there?