I am just about done remodelong my shower. I have a couple of Hansgrohe body sprays. They required 1/2 inch nipples recessed 3/8 inch from the finished wall. after tiling, they are recesses slightly more that 3/8".

The body sprays screw on and tight to the wall, but they don't seem tight enough onto the nipple, so I am worried about leaking.

I know I could have galvanized pipe cut to length, but how do I get brass nipples of the appropriate length. These Hansgrohe sprays don't seem to have any wiggle room, and another 1/2 inch would be too long.