Guess which one of these 1″ bronze hexnuts John used to pound the new 1″ keelbolts in place? O, yea, he’s following in David’s footsteps…two 1″ keelbolts threaded (both ends) and one 1″ die broken. Good thing they were the only two 1″ keelbolts in the boat (the rest are 7/8″).
In John’s defense, I can say from experience that using a die to thread anything over 3/4″ is very, very difficult. Just getting the die started is a challenge (I resorted to using the hydraulic press for the 7/8″ rod). Even though bronze might seem soft, the forces required to turn and cut the threads are huge.
Because of the relative softness of bronze, it is possible for the die to start bearing off of center. Then the treads cut too deep on one side and are only half formed on the other. So not only do you have to work real hard to turn the die, you have to constantly check the angle of the cutters and apply some corrective forces. Really, its a miracle that John got all the 1″ threads cut using just the one (brittle) die.
For the above reasons, we considered using the lathe that the yard just got working, but our inexperience with the lathe kept us from using it.
David