Here is a breakdown of the differences between the legacy T2 (Form 2) and the modern TX (Form 3/3+) ecosystem.
: Regardless of whether it's labeled T or TX, the real performance difference comes from the steel. Look for S2 steel for impact use (tougher) or Chrome Vanadium (CR-V) for standard hand-tightening. difference between t20 and tx20
It didn't "fit." It wedged into the corners and felt tight. As soon as you applied torque, it slipped because the contact surfaces were mismatched. You got lucky; do not repeat it. Here is a breakdown of the differences between