NEMA17 17HS3401S 42 Stepper Motor 1.5A 38mm 4-Lead Driving System 3D Printer Parts 
Features:
Large torque
Imported high-quality motor steel sheet, advanced technology to create bearings, small self-inductance reactance, good responsiveness, It can be operated at a low speed directly with the load link in the near locked-rotor state without gear deceleration. Therefore, a high torque-to-inertia ratio can be generated on a shaft with a large load and reduce systematic errors due to the use of reduction gears.

2. Low noise
The internal rotor adopts advanced technology, and the surface is coated with imported rotor gel to prevent burrs on the surface of the silicon steel after oxidative grinding, resulting in increased motor noise.

3. Fine workmanship
The whole body is made of high-strength metal, which is sturdy and durable, and has a side-closed metal matte texture to increase friction.

Specification:
Number Of Phases: 2
Step Angle: 1.8°± 0.09°
Rated Voltage: DC 3.6V
Rated Current: DC 1.5A / Phase
Phase resistance (20 ° C): 2.4 x (1 ± 15%) Ω / phase
Phase inductance (1kHz): 3.7x (1±20%) mH/phase
Holding torque: ≥420mN.m
Positioning torque: 15mN.m REF.
Steering (shaft extension): A-AB-B-clockwise
Maximum no-load starting frequency: ≥1500PPS
Maximum no-load operating frequency: ≥1900PPS
Insulation resistance: ≥100mΩ (DC 500V)
Electrical strength: AC 600V/1mA/1s
Insulation class: Class B
Moment of inertia: 57.3g*cm²
Wire: for DuPont 2.54-4P
Size: 42.3 X 42.3 X 38mm/1.67 X 1.67 X 1.5"

Notes:
1. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you!
2. Please allow 1-3mm measuring deviation due to manual measurement.