Originally Posted by
dabac
While we're at it, let's not forget that nipples are available in 3 different lengths as well. With 14 and 16 mm to choose between apart from the most common 12 a 6 mm deviation from the target length is a manageable issue.
Be sure to get spoke-lengths that are at least long enough to come up to the bottom of the slot in the nipple-head. That's on the short end and is the minimum. You can go 1-2mm longer and have the spoke-end flush with the top of the slot. Problem with being shorter than the bottom of the slot is that the nipple-heads will be unsupported and bear all the load without a spoke inside. The brass in the nipples is a lot weaker than the steel in the spoke and it's not uncommon to have nipple-heads snap off if the spoke is too short.