Yes it works. Just set the PWM pins to output and HIGH. For example the stepper_oneRevolution example works with this setup:
Stepper myStepper(stepsPerRevolution, 7,8,4,9);
void setup() {
myStepper.setSpeed(300);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
digitalWrite(5, HIGH);
digitalWrite(6, HIGH);
}
But since there is no hardware current limiting, steppers get hot real fast. And since the drivers do not work at low voltages such as 3V that are suitable for a lot of steppers, that can be a problem. Solution: get 12V steppers. Better solution: get a stepper driver with current limiting.