You need to know what the manufacturers GVWR rating is for the trailer, it is usually more than the combined axle rating. Then you need to know the axle rating, the tire rating, and what bridge law will allow you to carry on the axle spread.
Example our TrailMax TRD50T with 17.5" tires
GVWR - 60,800 lbs
Trailer weight - 12,100 lbs
Capacity @ 65 mph - 48,700
Axle rating - 20,000 lbs each
Bridge law allows 42,000 lbs on a over 8' to 9' 3 axle spread, so that leaves 18,800 lbs that needs to move to the truck via the tongue. We have Premier Hitches on our trucks rated at 100,000 total trailer gross weight and 20,000 lbs tongue weight.
So even though the axles can support 60,000 lbs, you can't do it because of bridge law. And if you don't have bridge law, I wouldn't want to tow it at the max with 60,000 lbs on the axles and only 800 lbs of tongue weight.