The sizes i found were 3.12, 3.14mm and 3.16mm and the ones that were packed in the screw were 3.10mm. i tried each by them selves @ 3.12mm there was wiggling so i increased the ball size the wiggle decreased but the at some points along the screw it got harder to turn then i tried alternating with 3.10 but no luck 3.12 & 3.10 wiggles & 3.14,3.16 with 3.10 wiggles and get harder to rotate at some points along the screw.