Q235 vs Q345 Strength?

[R1formetoo]

Hello. I'm new here and I'm hoping you guys can help me out a bit. My name is Ian and I'm getting into the business of importing Chinese 2 post car lifts into the U.S. and though I have an engineering degree I'm mostly a business man. So here's my issue. Attached you'll find a photo of a lifting foot on a car lift. I imported this lift for testing and when I tested the lift to it's max capacity I noticed that the foot deflected downward enough to make the powder coating pop off the side of the foot. While it did not exhibit permanent deformation it did deflect enough under the load to cause suspicion. So, I have asked the factory in China to propose a way to strengthen this piece. Their reply was to replace the existing Q235 steel with Q345, which they claim is nearly twice as strong. My problem is that I cannot find anything on the web showing the mechanical properties of these two Chinese steels to verify that this is indeed a good decision. Can anyone help with firm information on these two steels? I thank all those in advance who can and do help.

Ian Gilmore

 

[CoryPad]

If there was no permanent deformation, then increasing strength doesn't help. You need to increase thickness, height, or elastic modulus to decrease deflection.