#20. Zekelman Family
Residence: Windsor, Ont. & Bloomfield Hills, Mich.
Major holdings: Atlas Tube
Some families are content to hand off day-to-day management of the business; the Zekelmans tried it and decided it wasn’t for them. After handing the reins of JMC Steel, North America’s largest independent steel-pipe maker, to a non-family member in 2010 and becoming executive chairman, Barry Zekelman took back the CEO title last year.