Until just a few years ago, I would regularly check cardboard boxes, plastic bins, wooden crates, etc. and always max-out to the 3x70=210 lbs limit when I traveled internationally to my trade shows. I've never had a problem except when I have been inadvertently overweight, where I've had to re-pack stuff to bring all of my checked goods under 70 lbs. I always had to sign the damage waivers but I've never had any damage on international flights. Now, I generally only check about 100 lbs per trip, but there is never a problem with boxes, plastic bins or wooden crates.