As an FFA member at Somonauk (Ill.) High School in the 1960s, I sold wrenches like the MAC-AJ-4 wrench shown on page 41 of Farm Collector, August 2006 issue, as a fundraiser for our club. When you pulled the lever out as shown, it locked to the worm so you could turn it with the lever and you could clamp to a rounded-off nut like a hand vice. When I talked to a farmer, I would ask if he had a bolt or a nut he couldn't get off. They always had a pesky one. I would select the proper size wrench, clamp it on, remove the nut or bolt and sell him the wrench! Every time!
- Bob Rupert