Clocking square or rectangular stock accurately to run concentric in a 4 jaw chuck

[thehomeengineer]

Hi canyonman44
Thank you for your interest.
the length of bar that fits under the chuck jaws does not matter as the clock will be at the same height therefore the angle of the stock relative to the bed will be the same for both sides of the stock being clocked. I have always used that bit of stock as it is a nice diameter so sits on the bed and under the jaws nicely and it is roughly the right length when sat on a jaw to place the workpiece at a right angle to bed. But the length does not matter.
Hope this has helped
The Home Engineer