Jones and Shipman boring head

I have a Jones and Shipman boring head, on a 40int arbor, I'm looking for a 30int arbor, it has a 1" unthreaded boss that centres it with 4 bolts that hold it on, all searches for this turn up fine threaded Chinese import style arbors, does anyone know where one could be bought? Maybe I'm not searching the correct name for this style of arbor or something?

Here's a photo

It would be a fairly simple job to make a straight shank adapter so it could be held in a 30 taper rnd mill holder.

It would, which is what I'll do if needed, but I'd rather have a proper arbour if possible

Peter, if the boss is unthreaded how is the head fixed to the arbor ?

Emgee

The only think that might be the basis for an adaptor is this;

**LINK**

Emgee, the head itself has 4 long grub screws that screw into the head, the the arbour is held on by 4 thin nuts that hold it on, you can just see in the photo.

Old mart, I did actually see that while looking, it's probably what I'll end using, as it's about the same cost of buying a good lump of tool steel to make into a straight shank arbour.

Fortunately, it doesn't matter if the head runs a few thou out, the tip will always run in line with the spindle. A threaded adaptor with the bolt holes and the M16 thread in it should work pretty well, as long as you always rotate it the right way. That link was for an ISO30, I don't know the differences between the BT, INT and ISO variations. 

I wonder if the body could be threaded M16 directly, or is it too hard?

Edited By old mart on 05/01/2020 22:18:32

I just had a look through the sellers other items, they also have a m20 threaded version, I messaged the seller to ask the diameter of the location boss above the thread, if it's bigger than 1", that would be ideal, I could just cut the threads off then turn the boss to fit, and drill 4 holes as the original to hold it.

Can you find a face mill adapter with a big enough flange? You may have to run the bolts into tapped holes if there is no space for a groove for the thin nuts.