Actually, if one looks at the federal DOT guidelines for trucks, a class 1 or half ton truck has a gvwr to 6000 lbs, a class 2 or 3/4ton, has two classifications, light duty 6001-8400, heavy duty is 8401-10000 lbs. Class 3 or 1 ton is 10001-13500.
With in these DOT specs, one can find trucks badged with 15, 25 or 35 from a badging standpoint. So what is a 1/2 vs 3/4 vs a 1 ton? your guess is as good as mine! GM has had 1500, 2500 and 3500 models with 8600-10000 gvwr's, from single wheel setups to dually's back in the day. ALL are per the DOT, class 2 or what most would call a 3/4 ton truck. Even tho some rigs with 10K gvwr' had a 3500 badging, what many would consider a 1 ton truck!
Marty