Depends on diameter, length and taper, as well as the purpose for holding it.  The ideal way is to place it between centres and drive with a drive dog.  Anything small in diameter you would hold a parallel diameter and turn the taper outside the chuck.  If the taper is below about 8degrees you could probably make a bush with a matching internal taper and hold the part in that as it would be a locking taper, if larger you could push a centre against it to hold it in place.  Just some ideas, I am sure you will get plenty more.

What do you want to do the the tapered bar when it is held by a chuck?

large female ctr will support the domed end and allow you to turn the taper after shaping the dome

Can you make the blank 1″longer to start with? Place the blank into the chuck and turn the dome on the end. Reverse the blank and turn down the last inch to the minor diameter and droll through the !” plus the depth of the threaded section and thread this.

The extra can be held in the chuck and by making a small adaptor to fit over the revolving tail stock with a reversed V which can be pushed against the domed end then turn the taper, finally part off the extra 1″ hopefully the parting off will leave a pretty clean end.

Hope that makes some kind of sense.

No need for a split in the bushing. Just drill and bore or ream a tapered hole in a piece of round bar held in the chuck. Then tap the tapered pin into the tapered hole firmly. It will hold well enough to dome the end. Then tap the pin out with a rod through the spindle hole.

Another way might be to turn your taper, then drill and tap the hole in the small end, then part off at the other end using a HSS form tool ground to give the radius with parting tool incorporated. Angle the parting section so the “tit” in the very centre is left on the scrap, not the job.

How big is the pin BTW? And how many do you need to make? Is the taper a standard dowel pin taper, or morse taper etc where a reamer could be used to make a quick bushing?

On 14 November 2025 at 06:52 JasonB Said:

 

Put a female ctr in the tailstock and bring that up to support the domed end

Turn the taper

For small pieces you can buy something like THIS I have one which I use when wood turning.

You can also turn a 60degree cone into both ends of a short piece of rod, slip that onto your existing ctr and away you go. 3D printing would be another option.

On 13 November 2025 at 22:19 Andrew Crow Said:

…make a split bush at the same setting, you can then hold either way round…

That statement might need additional clarification.

If you have the thick end of the taper in the bush towards the headstock, the cutting force will try to push the item out of the bush. This might be of concern if trying to drill the thinner end of the piece.

On 14 November 2025 at 16:40 DC31k Said:

On 13 November 2025 at 22:19 Andrew Crow Said:

…make a split bush at the same setting, you can then hold either way round…

That statement might need additional clarification.

If you have the thick end of the taper in the bush towards the headstock, the cutting force will try to push the item out of the bush. This might be of concern if trying to drill the thinner end of the piece.

I think I would turn the taper first, with a tailstock centre in the small end. Then drill and tap the hole. And then flip it around in a bushing to dome the big end.

If you have a morse taper extension/adaptor with a parallel section make the taper to match that morse taper. You can then hold it in a chuck.

Martin C

I’ve been modifying MT4 arbors by cutting off the tang and drilling&tapping the end for a drawbar thread. I purchased an old MT4 cpstan turret sleeve and cut the end off. That allowed me to knock the arbors gently into the open-ended sleeve and hold the parallel outer diameter in the chuck. There’s no need for any other method of securing it holds the taper firm enough for turnong, parting and drilling.