I'm changing the ball joint rod ends for rose joints on my Autograss car, however i'm struggling to work out the thread size. The ball joints that are on are MOOG 125 (can't find any technical info on the Federal Mogul site)

I've measured the thread pitch and it's 1.5 metric or so close that it's indistinguishable. I had it in mind that they were 5/8 fittings, but the thread pitch thing has thrown me.

How do I work out what I need thread wise in a rose joint?

dont no wear you live but in york neer me there is a shop called fast pack fastners and thay have everthing and if i dont no somthing i take it down to them and get them to mesuer it my be look in your local yellowpagers to see if there are any shops like it near you

Your threads could be M16x 1.5 pitch or
perhaps 5/8"x 18 tpi UNF.
Since 5/8" diameter is 15.88mm there is only a small difference in diameter and 18
tpi equates to a pitch of 1.4mm.
Since 1.5mm pitch converts to 16.9 tpi you should be able to pick up the one
thread difference if you have an inch of thread to count along.


Mal

Cheers for the info, i'll go and count the threads and see if I can work it out.

Found my verniers and measured the TPI and it's more like 17. Measured the diameter across the threads and it looks like 14mm. Tried my imperial thread gauge and 18tpi is close but no fit. 1.5mm is perfect, so I think it's M14 x 1.5.

Quite close to 9/16 18, but not quite.