This motor is equivalent to 17HS4401 Model No. Step Angle Motor Length Rated  Current Resistance /Phase Inductance /Phase HoldingTorque Inertia Of Rotor   Lead  ( °) (L)mm (A) (Ω) (mH) (N.cm)  (G. cm²) (No.) 42HD4027 1.8 40 1.72.23.8 40 57 4