Jim and Frank were almost perfect opposites, like being married. Jim was truly crabby and gruff, many times crude and rude, but had a soft heart. Frank came across smooth and nice, a good talker and friendly, but underneath he was the tough one of the two, the one you definitely did not want to get on the wrong side of.
If Jim ever had a family, he never mentioned it, I don't believe he did, he considered children a PITA. Frank had at least one son I know of, maybe more, he kept his family life separate from the unholy crew at the shop, can't say I blamed him, we were a pretty rowdy and raunchy bunch.