I'm cleaning out my shop. In my collection of stuff I have a couple of 2-ton K-Mart jack stands from around 1980. They are the ones made from a piece of steel tubing split to form three legs, and have the adjustable center part held in place with a pin on a chain. When I'm going under the car, I use a more modern ratchet type 4-legged set, but I still use the old ones to hold up one end of a car when rotating tires. This type used to be very common, sold under a zillion brands, but hasn't been sold for a long time. I think they might have been pulled because they were unstable or could collapse. Anybody remember these and the story behind them? Should I keep using them for non critical applications, or should I recycle them and buy another newer set?