This high precision bipolar Nema 17 stepper motor with 0.9° step angle (400 steps/revolution). Each phase draws current 0.9A, allowing for a holding torque of 36Ncm(50oz.in). <br> <br> <b>Electrical Specification</b> <br> <br>* Manufacturer Part Number: 17HM15-0904S <br>* Motor Type: Bipolar Stepper <br>* Step Angle: 0.9° <br>* Holding Torque: 36Ncm(50oz.in) <br>* Rated Current/phase: 0.9A <br>* Phase Resistance: 6.0ohms <br>* Recommended Voltage: 12-24V <br>* Inductance : 12.0mH±20%(1KHz) <br> <br> <b>Physical Specification</b> <br> * Frame Size: 42 x 42mm <br>* Body Length: 40mm <br>* Shaft Diameter: Φ5mm <br>* Shaft Length: 22mm <br>* D-cut Length: 15mm <br>* Number of Leads: 4 <br>* Lead Length: 300mm <br>* Weight : 280g <br> <br> <b>Connection:</b> <br> <br>Black(A+), Green(A-), Red(B+), Blue(B-) <br> <br> <b>Warning:</b> <br> <br>Make sure the motor connect to a constant current or chopper drive controller before you test motor. <br>Connecting the motor directly to a power supply will destroy the motor.