42HS32  This 4-wire bipolar stepper has 1.8° per step for smooth motion and 3.2 kg.cm holding torque. The motor was specified to have a max current of 350mA so that it could be driven easily with 

Some nice details include a ready-to-go cable and a machined drive shaft (so you can easily attach items). 

• 200 steps per revolution, 1.8 degrees
• Bipolar stepper
• 4-wire, 12 inch leads
• 42mm/1.65" square body
• 31mm/1.22" square mounting holes, 3mm metric screws (M3)
• 12V rated voltage (you can drive it at a lower voltage, but the torque will drop) 
• Max current:  1.0 A
• 32 N*cm, 3.2 Kg*cm holding torque per phase
• 35 ohms per winding