Your mileage may vary. Test it out a few times to ensure they’re safe. I cut them to 12 inch pieces. I put a tractor on them once time and they did fine .
I made up a set to fit under the front wheels. Needed for engine removal/install. Shop crane runs into axle stands.
Height was floor jack maxed out, gave me lots of rumm under truck. D9 dozers sitting on wood blocks is the only way.