Large rolled plate and K-factor

Happy Monday Morning to ALL....

When setting up large plate (3/4" thk x 17" w x 46" dia) to unfold, do any of you have any suggestion for setting the K-factor? I currently have it set at zero since it is not being stamped. I would like to have proper length for a flat pattern water jet cut.

Thanks for your time

Rich

SolidworksSolidworks 2011 Beta