Official Luthiers Forum!

Hello everyone.

Does anyone have a list/spreadsheet of truss rod specs throughout the ages (I.e nut dims, thread specs, bar lengths and material choice. From typical and obscure manufacturers. Sources of replacement parts would also be greatly appreciated to!

If not, I would really like to create one with your help!!

The main reason I need to know is because I have a very nice client's old Jedson SG bass in at the moment for repair works. However it is missing the truss rod nut and I can't seem to match any standard truss rod nut to it!

I've found very little information on these Instruments online, especially when it comes to the original parts specs. I can't access the thread to measure(however it looks like m6 to me. Wish i could get in there!)
I just want to know where I can source a replacement. As I do not want to start re cutting the thread, as i'm never happy with the results. It's never good enough!!!


All the best!

where was it made? Metric would make sense if it was made somewhere besides the USA.

Another possibility is one of the gun screw sizes - which tend to be oddball combinations of very non-standard thread pitch and diameter combinations.... Stuff like a #12 with 48 tpi.

Thanks

Cheers truck John.

It's Japanese made late 60s /early 70s

Just wish I could get inside the truss rod cavity to measure!!

My brother is an engineer and told me to bore and cut an m5 to m6.
This will make a thin Walled nut. However the threaded rod is quite long for a standard nut to then make contact with the tensioning plate.

So ideally needs to be a nut with long body.

It's never easy ay?

Just wish there was a document somewhere that says. This model used the following component.....
With these specs.......

I don't want to start machining stuff up to test it, because I may be barking up the wrong tree with regards to thread pitch and this will invite cross threads and I really don't want to get into replacing existing/original parts to be honest.

If there is no other alternatives I will have to start down the matching /trial and error route.

Will bear your comment in mind if it comes to it!

Thanks for your advice.