Motor Torque Characteristics

[baberjaved]

I am using a 1.6Ampere 2Phase Bipolar motor and feeding it with 24Volts using a L297/L298 circuit and by using a pulley of 1 inch diameter I was able to lift up a weight of 2Kg with a Clock pulse of 1Khz on Half Stepping but not on Full Stepping... Is this the usual maximum limit for this much rated motor or is something wrong with my circuit? (its not even drawing the maximum 1.6A current)

 

[Hero999]

Without the datahseet it's difficult to know.