Step motor torque

Has anybody taken a good look at the torque curves provided on the
Microkinetics web site for their stepper motors?
For their 34M470 (big NEMA 34) the rated holding torque is 460 oz*in
but the torque curve shows better than 500 up to about 300 rpm.
On the other hand, the 42M1150 which has holding torque rated at
1125 oz*in never gets above 525 oz*in at any speed according to their
curves.
This is assuming both are running on the 72V supply. What's the
deal, is this a typo?