Question about R8 arbors

[VelocityDuck]

One of the things that I've found in the toolbox that I purchased are three arbors.

An R8-JT33, R8x3 and R8x4.

I get the R8-JT33 is probably for a drill chuck.

But what would the R8x3 and R8x4 be used with?

[jcfx]

The R8-3 and R8-4 are probably for drill chucks too.

[VelocityDuck]

What does the 3 or 4 denote?

I wouldn't think Jacobs because I didn't think there was a JT4.

[arborist]

What do the x3 and x4 look like? Can you post a picture of them? If not, can you describe them? Do they have the same shape and proportions as the JT33 one? Are they tapered or parallel?

[VelocityDuck]

As requested. JT33 on the left, R8x4 in the center and the R8x3 on the right.

PXL_20230515_205530115.jpg (1.08 MiB) Viewed 2742 times

[jcfx]

What does the 3 or 4 denote?

I wouldn't think Jacobs because I didn't think there was a JT4.

This is what Jacobs lists for R8 shanks -
http://www.jacobschuck.com/arbor/54.html

The some import chuck adapters seem to drop the JT when they label the arbors.

[VelocityDuck]

Those measurements match up to the 3 and 4 arbors. I hadn't heard of the Jacobs 4 before.

Thanks for the assist!