Robin2:
That motor requires 1.68 amps and the SN754410 is only rated for 1 amp. Also, as the motor coil resistance is only 1.65 ohms anything over 2.8 volts will overload the motor unless you are using a specialized stepper driver that can limit the current to protect the motor. The Pololu DRV8825 stepper driver should be suitable, but it will probably need a heat sink....R
Thank you for your insight, Robin2!