Im getting ready to thread the drive shaft, but I read the shaft diameter needs to be reduced before threading. Does anyone know exactly or approximately how much I need to remove?

your gonna thread by hand? i think it just means taper the end so you can get the die started. you gotta get it staight or its gonna be hell.

That is asking for trouble!!!! You CANNOT POSSIBLY thread something by hand straight enough to use on something as sensitive as a prop shaft. If you're a cunt hair of a degree off of perpendicular to that shaft, you'll rattle the bolts out that sucker!!! Take it to a machine shop, it's not expensive!

mine did mine for 50 bucks and put a 1/4 key way on top too

Ive got access to a lathe, but my thread cutting skills leave something to be desired. LOL. I can never get them clean. I also have a 10 TPI die. I was going to start the cutting on the lathe to make sure they are straight, and then clean them up with the die. What I was asking for was the major diameter of the shaft. I don't know how tight to tolerances are with the prop and want to make sure I don't have too much or too little play. Ive seen major diameters vary from .7500 to .7300. Has anyone ever checked the finished diameter of the threads?

why dont u let the owner of the lathe u have access to do it for u??? and the key to threading on a lathe is u dont make the full cut in one pass u go like 3 to 4 passes!!!!

taper the end of the shaft and make sure the die is straight. I just did mine cost $10 for the die. it was easy.

Why not cut the threads with the lathe? My neighbor has a mill and lather and I watched him plug in some numbers and bam... THreads cut all with the tooling on the lathe.

All good points;However, the lathe owner only uses it for facing and tapering. Didn't even know it was capable of threading until I showed him. LOL. The lathe is probably circa 1950 so no computer controls. And I haven't run a test threading yet to see if its able to make 2 or three accurate passes. I was planing to turned down the shaft to the proper major diameter and do one medium depth pass to get everything straight. Then use the die to finish. I was hoping someone could put a micrometer on the threaded area(preferably from a one of the major manufactures models) and post that number. Thanks again for all the ideas.

For this application you are going to want a class 2A fit. According to the engineer's handbook, your maximum major diameter is 0.7482 and your minimum major diameter is 0.7353. You minor diameter is 0.6255.

Thanks, that what I needed.