I had a buddy that was trying to make a freak tip adapter (some of you may have seen the freak-to-freak picture I posted last year). I had him using my shop to make the part by hand....he went ahead and bought a die to cut the threads, used my cocker tap on the inside, made the rest of the piece and threaded the outside....then found out it didn't screw in. He came up to me looking like a sad puppy and asked why it didn't fit and if it was multi-lead...I was like YES IT'S MULTI LEAD WHY YOU NO ASK!?!?
Anyway I ended up making the outside of the adapter for him then he took it and finished the inside for the second time. lol