I'm having a bit of bovver! This particular problem has been ongoing for 7 months, I kept putting it off and putting it off, but now it has to be conquered because I cannot progress any further.
I have to thread my own tunnel thrusters no problem I've threaded stuff loads of times before. This time though something is not right.....
4.2mm rod, 4mm threading die. Requisite amount of thread added to rod. However the propellor, in fact a nut, any nut of 4mm will not run down the thread.
I've searched the internet and found that 4mm comes with a pitch of .7mm, in fact it is marked on the face of my 4mm / 0.7, so why can't I get a damn nut or a propellor down the thread? The nuts are of several types, steel, brass and bought from different places, as are the propellors.
One last thing, its a right handed die, not a left, so the thread is going the right way
Anyone with any advice what to try next?