Yes we have this training as part of the Ziranmen system.
Its called the Mother and Son Ball
Here two iron balls are used, one 8kg and the other 10kg for conditioning the hands. You should train twice a day, gradually increasing you power, qi and repetitions. Do not use hard force. Here the practitioner would assume horse stance and practice lifting, catching, pushing, pointing, and drilling the balls with their fingers. There are also different dynamic movements that can be used also instead of remaining in horse stance.
I have been using the 8kg (son) ball (its hard work) and have not moved onto the 10kg (mother) - you need to be careful and gentle as if you go in to hard to soon you can injure your hands, wrists and tendons easily.