just quick report: got a HF ball joint separator thinking it would work to separate a drill chuck from a damaged arbor - drilled a hole through the arbor, put a pin through it and clamped it down with the chuck body just above the vice jaws- put the separator (looks like a tapered fork) against the chuck - smacked it a few times with a hammer, and the tool split in half - so the tool is worthless. Tried a good quality (name brand) tool and it worked quickly and easily.
Next step, return tool to HF and get refund.