The brake does index square upon contact( Just snug ). But brakes with a flat on them are whole different creature than brakes in the round and that's due to the tension required to keep it in place but also square at the same time. The set screw allows me to screw the brake on untill it touches snug , where it is square and set the screw. Anyone who has used brake much knows there is some give to any metal involved, barrel/ brake and over tightening of a brake that indexes correctly, especially with brakes with a flat. They will go past there index point and will not longer index correctly where the flat is noticeable past it's index point. With round brake, I can care less doesn't matter the hole pattern is equal all the way around and you cant see it visually.The only way to make a brake index up correctly would be to do it at a certain inch pound of torgue and never go beond that, well that isn't happening with me, for speed, cleaning and simplicity. Screw the brake on untill it touches snug and indexes, set the screw with maybe a 1/8 - 1/4 turn and be done with it.