Joining 2 different imperial threads

[22]

Bit of a pickle, I need to be able to suspend/attach an object of around 12kg that has an upright threaded rod 3/8. The piece above finishes in a 9/16 rod. It also needs to be fitted and removed as required. I did have the part made for the purpose, but seems to have disappeared. The part was a good 75mm in height so plenty of thread each side. The 2 parts when attached are unable to rotate or move, so hopefully something a little more home made will do for now.

I'm thinking I'm (getting a friend) welding the two different sized nuts together. Any better suggestions? Can't seem to find a female to female reducer for these sizes. Also I'm against the clock, so needs to be something I can fetch from the shops (happy to drive as far as I have to). In Sussex over the weekend, usually home counties.

[b2hbm]

I'd go with your idea of welding the two nuts together, the only thing I'd add is to use a small section of tube between them so that you weld one nut to either end. That way you're sure to get the full thread engaged at both ends.

[E-bmw]

Alternatively, if access is not an issue, you could weld a heavy gauge washer to each end of 2 strips of metal to allow spanner/small socket access to tighten/loosen the attachment.

[22]

Relief, I found the missing piece. Not as big as I thought. Any idea what this would be called? I can't find any reducers that take these rods in UNF or equivalent. Or anyone able to make one from the one I have? I'm thinking metric might work with the matching thread.

[Buzz84]

looks like some one has just drilled and tapped some hexagonal bar stock to me.

That sort of item could be called a "female reducing adapter/socket"