Bringing this one back to the top as a Public Service Announcement........
Recall on Harbor Freight jack stands
https://www.roadandtrack.com/car-cul...of-collapsing/
These jack stands were sold under the Pittsburg brand name, and can be identified by item numbers 56371 or 61196 on 3-ton models, and 61197 on 6-ton models.
I need to go check mine now. I always use a back-up when I crawl under a vehicle.......of course most of the time the back up is a floor jack.....from Harbor Freight