If employee’s salary is 38K, is there a good chance his year-end raise will be 40K even if the decided percentage doesn’t equal that?

Basically, if an employee’s salary is almost in a new bracket, is it likely the superiors will be in favor of bumping that employee’s salary to the next bracket no matter what percentage increase they initially decided?  For example:

They give him a 5% raise, which equals $39,000.  Will they let him slide and say “Let’s make it an even $40,000,” which would obviously make employee very happy not just because of the raise, but because he’s now part of the “40 club.”  With slacker employees that have bad attitudes, I imagine there’s no chance of this.  But what if it’s a very well-liked hard-working employee who never calls in sick?  Will the superiors figure “He’s almost at 40K, so let’s give him that instead”?

Or are superiors like teachers — if you get a 95% on a test, they’re not going to bump it up to 100%?