Thanks for your question.
The length of the threaded end of this Tomlinson SPBH Dispenser Faucet is 5/8". That said, are you trying to replace a faucet? If so it may be best to give a member of our Tundra Restaurant Supply team a call at 1-888-388-6372 with your product's model number on hand, and we can track down and order the correct replacement part for you.
Answered on 3/4/2013 by Andrew Call from Boulder, CO